Chapter XV: Appendix: “Rhizopods in Poliomyelitis acuta.” (9)

[The following stages may be noticed in sheep suffering from fascioliasis. Gerlach recognized four stages, based on the varied relations that the flukes contract with the liver of their host. These periods are sometimes very marked, but at others, owing to subsequent infections, the features become merged and so obliterated. But when a single infestation occurs they are very marked.

[The first period is called the PERIOD OF IMMIGRATION. This occurs at the fall of the year and generally passes unperceived, as the young flukes do little harm to the liver. It varies from four to thirteen weeks. Gerlach has remarked upon cases of death from apoplexy at this period.

[The second period is the PERIOD OF ANÆMIA. This occurs in November and December. The sheep at first fatten rapidly, but later the mucous membranes become pale and of a yellowish hue, and the sheep become sluggish and cease to feed. The fæces are normal, but may contain fluke ova.

[The third period is the PERIOD OF WASTING. This corresponds with the beginning of January--about three months after the entry of the larvæ. Emaciation now becomes very marked, the skin and mucous membranes blanched, temperature variable and marked by an irregular curve; respiration laboured and quick; appetite regular; abortion frequently occurs in pregnant ewes; pressure on the back causes the animals to fall; local œdemas occur, the most perceptible in the submaxillary space, extending below the larynx and over the cheeks and parotids (called “bourse,” “boule” in France; “watery poke” or “cockered” in England). Death usually occurs at this period, but a fourth stage may occur.

[The fourth period is the PERIOD OF MIGRATION OF THE FLUKES. This is a period of convalescence and recovery, generally in May and June.--F. V. T.]

Oxen suffer less in general, but even in these animals “stray” hepatic flukes are occasionally found in the lungs, enclosed in thick-walled cysts.

_Pathological Anatomy._--The bile-ducts are conspicuous on the surface of the liver. They are thickened and much dilated and in parts saccular, and considerable atrophy of the liver cells accompanies the condition. Histologically there is immense proliferation of the epithelium of the bile-ducts leading to “adenomata.”

The LIFE-HISTORY of the liver fluke was discovered by R. Leuckart and P. Thomas. According to these investigators the elongated miracidium (fig. 131, _a_) ciliated all over develops from the eggs a few weeks after the latter (fig. 142) have reached the water, and after it has become free the embryo penetrates and becomes a sporocyst (fig. 131, _b_) in a water-snail (_Limnæus truncatulus_, Müll. = _L. minutus_, Drap.) that is common in fresh water, and can live in the smallest collection of water as well as in fields that have been flooded. The sporocyst first of all produces rediæ, which remain in the same host (and under certain circumstances, _e.g._ in summer, these develop a second generation of rediæ), and these finally form cercariæ (fig. 134). The latter become encysted on blades of grass and are taken up by the respective hosts with their food; this takes place towards the end of summer, while the sheep feeding on the pasture land in the spring spread the eggs of the fluke, and sometimes the fluke itself, by passing them with their fæces.

In districts where _Limnæus truncatulus_ is absent, analogous species act as the intermediary hosts, of which one example according to Lutz is _Limnæus oahuensis_ in the Sandwich Islands.

[The host in Europe is _Limnæus truncatulus_. This snail extends from Siberia to Sicily and Algeria, and according to Captain Hutton is a native of Afghanistan. It also occurs in Thibet, Amoor, Morocco, Tunis, Canary Islands and the Faroe Islands. It deposits its eggs or spawn upon the mud around ponds, ditches and streams. The eggs are laid in batches of thirty to a hundred, each snail laying as many as 1,500 eggs; they are united into strips of a gelatinous substance. In about two weeks young snails appear. It is amphibious, being more frequently met with out of the water than in it. It occurs in elevated spots as well as in low-lying districts. Moquin-Tandon found it at 4,000 feet in the Pyrenees. In the allied species, _L. peregra_, the fluke will develop up to a certain stage, but never completes all its varied phases.

[In South America the host is probably _Limnæus viator_, Orb., and in North America _Limnæus humilis_, Say.--F. V. T.]

In human beings as well as in some of the mammals quoted above, the liver fluke is only a casual parasite, and hitherto only twenty-eight cases have been observed in man; the infection was mostly a mild one and there were no symptoms, or only very trifling ones; a few isolated cases were only discovered _post mortem_. Occasionally, however, even when the infection was inconsiderable, severe symptoms were set up, which in isolated cases led to death. The symptoms (enlargement and painfulness of the liver, icterus) merely pointed to a disease of the liver.

_Diagnosis_ can only be established by finding eggs in the fæces. Care should be taken not to confuse them with those of _Dibothriocephalus latus_.

HALZOUN.

In North Lebanon, the liver fluke is, according to A. Khouri, a frequent parasite of man, not in the liver, however, but in the pharynx. The occurrence in this unusual site is effected by the eating of raw infected livers, especially those of goats (_Capra hircus_). The flukes thus taken in do not all reach the stomach, where they would be soon killed, but some of them attach themselves to the pharyngeal mucosa and to the adjoining parts, and there cause inflammation and swelling, which lead to dyspnœa, dysphagia, dysphonia and congestion of the head, sometimes even to still more severe symptoms, and even death. The affection termed “Halzoun” lasts some hours or several days, and after vomiting recovery sets in. In other cases man becomes infected in the usual way by ingesting cysts attached to grass or the underside of leaves of plants (_e.g._, Rumex sp.), where they are overlooked from their scanty size (0·2 to 0·3 mm.).

As the liver fluke feeds on blood it is possible that it also reaches, particularly when young, the circulatory system, and cases have been known in which it has been carried by the blood into organs far from its original situation. Such cases also have been repeatedly observed in men. Probably the parasite described by Treutler, 1793, as _Hexathyridium venarum_, which protruded from the ruptured anterior tibial vein of a man, was a young liver fluke. A few adult specimens were found by Duval in the portal and other veins _post mortem_ at Rennes (1842) in a man, aged 49, and a similar statement is reported by Vital from Constantine (1874). Giesker, in 1850, found two hepatic flukes in a swelling on the sole of the foot of a woman. Penn Harris states that he observed six specimens in Liverpool in a spontaneously ruptured abscess of the occiput of a two months old infant. Another case which, like the previous one, is reported by Lankester,[271] relates to a sailor who suffered from an abscess behind the ear, and from which a liver fluke was expelled. Finally, Dionis de Carrières reports the case of a man, aged 35, in whose right hypochondriac region a tumour the size of a pigeon’s egg had formed, and from which a young liver fluke was extracted.

[271] In the English translation of Küchenmeister’s work on Parasitology (London, 1857). The specimen is preserved in the Hunterian Museum, London, and is an adult liver fluke, measuring 18 mm. in length and 7 mm. in breadth.

From such records it is not impossible that _Distomum oculi humani_, Ammon, 1833, as well as _Monostomum lentis_, v. Nordm., 1832, may have been very young hepatic flukes that had strayed. Ammon found four specimens (length 0·5 to 1 mm.) of his species (named _Distomum ophthalmobium_ by Diesing in 1850) between the opaque lens and the capsule of a five months old child in Dresden, and von Nordmann discovered his _Monostomum lentis_ to the number of eight specimens (only 0·3 mm. in length) in the opaque lens of an old woman. Minute white bodies which Greef found in the cortex of the lens of a fisherman, aged 55, removed on account of cataract, were with some reserve regarded as Trematode larvæ. The fact that Ammon found that the intestinal cæca of the worm discovered by him had no lateral branches does not negative the above opinion, as in the liver fluke the intestinal cæca are originally unbranched, and according to Lutz they only develop lateral ramifications later, between the twelfth and twenty-second day of infection (fig. 144).

*Fasciola gigantica*, Cobbold, 1856.

Syn.: _Distomum giganteum_, Diesing, 1858; _Fasciola gigantea_,
Cobbold, 1858; _Cladocœlium giganteum_, Stoss., 1892; _Fasciola
hepatica_ var. _angusta_, Raill., 1895; _Fasciola hepatica_ var.
_ægyptiaca_, Looss, 1896.

This species is closely allied to _Fasciola hepatica_, but is distinguished by its elongated body, short cephalic cone, almost parallel sides, larger ventral sucker, which is also closer to the oral sucker, and by its larger eggs. Length up to 75 mm., width up to 12 mm. Oral sucker 1 to 1·2 mm., ventral sucker up to 1·7 mm. in diameter. Eggs 150 µ to 190 µ long by 75 µ to 90 µ broad.

_Habitat._--Bile-ducts of _Camelopardalis giraffa_, _Bos taurus_, _Bos indicus_, _Bos bubalis_, _Ovis aries_ and _Capra hircus_.

_Distribution._--Africa.

This species has once been observed in man by Gouvea, in Rio de Janeiro, in a French naval officer who became ill with fever, cough and slight blood-spitting. The lungs were normal except for a sharply circumscribed spot at the base of the left lung. Twenty days later during a fit of coughing the patient spat up a fluke 25 mm. long, characterized by its slender aspect and by the size of its ventral sucker, and its close proximity to the oral sucker. Considering the fact that Gouvea’s patient had spent many weeks in July of the same year in Dakar (Senegambia), where according to Railliet _Fasciola gigantica_ is common in slaughtered animals, and considering also the characters of the fluke, Railliet rightly assumes that one had to do with the African giant fluke and that the patient had infected himself in Dakar.

Sub-family. *Fasciolopsinæ*, Odhner, 1910.

Genus. *Fasciolopsis*, Looss, 1898.

Ventral sucker large, and elongated posteriorly into a sac. Cirrus
pouch long and cylindrical, its greatest length being occupied by the
sinuous tubular seminal vesicle, on which exists a peculiar cæcal
appendage. Laurer’s canal present.

*Fasciolopsis buski*, Lank., 1857.

Syn.: _Distomum buski_, Lank., 1857; _Dist. crassum_, Cobbold, 1860,
_nec_ v. Sieb., 1836.

The length of the body varies; it may measure 24 to 37 or even attain 70 mm.; the breadth is from 5·5 to 12 to 14 mm. In the pig the fresh parasites measure, smallest, 12 to 8 mm.; largest, 35 to 16 mm. (Mathis and Léger). Skin without spines, but according to Heanly always present in man and pig specimens. The oral sucker measures 0·5 mm. in diameter; the ventral sucker is three to four times as large; the pharynx is globular, 0·7 mm. in diameter; the prepharynx is provided with a sphincter; the intestinal cæca extend to the posterior border with two characteristic curves, one at the anterior border of the anterior testis, the other between the two testes. The genital pore is at the anterior border of the ventral sucker; the cylindrical cirrus pouch extends from behind the ventral sucker to half-way to the shell gland. The seminal vesicle extends forwards within the cirrus pouch as a convoluted tube. From its anterior portion is given off the cæcal appendage, which has itself short lateral diverticula. It runs backwards, ending blindly about 0·5 mm. from the posterior end of the cirrus sac. The seminal vesicle is continued as the pars prostatica (?) 0·5 mm. long, and this by the very short ejaculatory duct (13 µ), and finally by the fairly long cirrus, which is beset with very fine spines except at either extremity. The ovary and shell gland are situated at about the middle of the body with the testes behind them, and the uterus in front. The vitellaria extend from the ventral sucker to the posterior border. The eggs measure 120 µ to 130 µ in length and 77 µ to 80 µ in breadth, and resemble those of Echinochasma sp. in dogs. The larval stages are said to occur in shrimps.

_Habitat._--Intestine of pig and man.

_Distribution._--In man: India, Siam, China, Assam, Sumatra. It is common in Cochin China (16 out of 133 Annamites, Noc.), in Tonkin very rare. Dr. J. Bell has sent me [J. W. W. S.] human specimens from Hong Kong. In pigs: very common in South China (Heanly). Common in pigs in Hong Kong. Sixteen out of 248 pigs (_i.e._, 6 per cent.) infected in Hanoi.

*Fasciolopsis rathouisi*, Ward, 1903.

Syn.: _Distomum rathouisi_, Poirier, 1887.

Fifteen to 19 mm. long by 8·5 to 10·5 mm. broad by about 3 mm. thick. Skin with spines (Leiper). Bluntly oval or elliptical with short cephalic cone which is absent in _Fasciolopsis buski_. Oral sucker subterminal, 0·25 to 0·29 mm. broad by 0·2 mm. in antero-posterior diameter. Distant from ventral sucker by about twice its diameter. Ventral sucker 1·32 to 1·38 mm. broad by 0·68 to 0·7 mm. in antero-posterior diameter. Œsophagus extremely short. Cirrus sac not conspicuous and straight as in _Fasciolopsis buski_, but is convoluted. Testes one behind the other (according to Poirier they lie beside one another), more compactly branched, broader and denser than in _Fasciolopsis buski_. Ovary on right side, small, coarsely branched. Uterus in broad, closely grouped coils, packed with ova anterior to ovary. Vitellarian acini more numerous and somewhat differently distributed. Eggs 150 µ by 80 µ, thin shelled. [H. B. Ward, who has examined this species, and from whose account the above is mainly taken, considers that it is a good species, although the differences between it and _Fasciolopsis buski_ are slight, while Odhner, who examined the original species, is of the opposite opinion.--J. W. W. S.] The parasite appears to cause diarrhœa, wasting and occasionally jaundice.

_Habitat._--Intestine of man.

_Distribution._--China, common in some parts (Goddard).

*Fasciolopsis goddardi*, Ward, 1910.

Twenty-one to 22 mm. long, 9 mm. broad. Skin with spines (Leiper). Uterus very closely coiled, most striking character is the large size of the vitelline acini. Imperfectly known.

_Distribution._--China (Shanghai).

*Fasciolopsis fülleborni*, Rodenwaldt, 1909.

The fully extended fluke is tongue-shaped, 50 by 14 mm.; two contracted specimens measured 40 by 15 mm. and 30 by 16 mm. respectively. Skin without spines, with according to Leiper cephalic cone not clearly defined. Oral sucker circular, 0·75 mm. in diameter, slightly larger than that of _Fasciolopsis buski_. Ventral sucker 2·6 mm. in diameter (that of _Fasciolopsis buski_ 1·6 to 2 mm.). Length 2·9 mm. (as in _Fasciolopsis rathouisi_), the excess of length over breadth being due to the posterior elongated sac-like prolongation of the sucker. Prepharyngeal sphincter present. Pharynx 0·7 mm. in diameter. Œsophagus practically absent. Gut cæca similar to those of _Fasciolopsis buski_.

_Testes_--regularly branched, separated by an incurving of the cæca, the anterior occupying a smaller area than the posterior.

_Ovary_--very small, as in _Fasciolopsis buski_, on the right side.

_Shell Gland_--almond-shaped, 2·3 by 1·2 mm. In _Fasciolopsis buski_ it is round and smaller, 1 to 1·5 mm. in diameter.

_Vitellaria_--similar in distribution to those of _Fasciolopsis buski_, but the acini are strikingly small.

_Cirrus Sac_--is the most characteristic feature of this species. It is a powerfully built, convoluted sac standing out clearly on the body. It is not a uniform, straight cylinder 0·25 to 0·33 mm. in diameter, as in _Fasciolopsis buski_, but even in fully extended flukes is typically convoluted. It is 1 mm. thick in the middle, but in other parts varies much from this. The posterior end of the cirrus sac is at two-thirds or more of the distance from ventral sucker to shell gland. In the case of _Fasciolopsis buski_ the posterior end of the sac only extends half-way.

_Seminal Vesicle_--has a peculiar convoluted, saccular and angular course, but the cæcal appendage characteristic of the genus appears to be absent!

_Excretory System._--The main stem gives off very regular transverse branches which are well seen posteriorly.

_Eggs._--100 µ by 73 µ. Thin shelled.

_Habitat._--Intestine. Mahommedan from Calcutta.

[It is evident that a re-examination of fresh material is required before the validity of all these species can be accepted.--J. W. W. S.]

Family. *Troglotremidæ*, Odhner, 1914.

Genus. *Paragonimus*, Braun, 1899.

Body egg-shaped or somewhat elongated, generally more broadly
rounded in front than behind. Covered all over with spear-shaped
spines _arranged in groups_. Gut cæca winding with dilatations
or constrictions in parts. Ventral sucker in or in front of the
middle of the body. Excretory bladder cylindrical, very long and
broad, reaching in front to the bifurcation of the gut. The lateral
excretory canals join the bladder only a little in front of the
excretory pore. Genital pore median just behind the ventral sucker.
Genital sinus duct-like. Cirrus sac absent. Male terminal organs very
small. Ejaculatory duct present. Testes and ovary deeply lobed, the
testes in or just behind the middle, the ovary somewhat laterally
placed just _behind_ the ventral sucker. Uterus forms a coil behind
the ventral sucker. Eggs rather large, thin shelled, the ovarian cell
still unsegmented on deposition. Receptaculum seminis, small.

Parasitic in the lungs of mammals, enclosed in cyst-like cavities,
generally in pairs.

_Type Species._--_P. westermanii_ in the tiger.

*Paragonimus ringeri*, Cobb., 1880.

Syn.: _Distoma ringeri_, Cobb., 1880; _Distoma pulmonale_, Baelz,
1883; _Distoma pulmonis_, Suga, 1883.

The body is of a faint reddish-brown colour and plump oval shape. The ventral surface a little flattened; 7·5 to 12 mm. in length, 4 to 6 mm. in breadth, and 3·5 to 5 mm. thick (in man). The oral sucker (0·75 mm.) is subterminal; the ventral sucker (0·8 mm.) somewhat in front of the middle of the body. Pharynx spherical, 0·3 mm. in diameter, or 0·4 by 0·3 mm.; œsophagus, 0·02 mm.; intestinal cæca convoluted, asymmetrical, the first part having the same structure as the œsophagus. The cuticle is covered with spines in groups; the excretory pore opens at the posterior end rather on the ventral surface, the excretory ducts open into the elongated bladder at the hind end near the pore. Genital pore behind the ventral sucker and median. Genital sinus 0·2 mm. long with thick wall, ejaculatory duct 0·13 mm., pars prostatica 0·2 mm., seminal vesicle duct-like of irregular outline. Behind the sucker the ovary on the left, and the closely packed uterine coil on the right (though amphitypy of these two organs is common); the two irregularly lobed testes lie side by side posteriorly. Vitellaria extensive, leaving only a median dorsal and ventral space free. Seminal receptacle probably absent; Laurer’s canal present. The eggs are oval, brownish-yellow, fairly thin shelled, and measure on an average 81·2 µ by 49·2 µ.

The following species are also known:--_P. westermanii_, Kerb., 1878, in the tiger, and _P. kellicotti_, Ward, 1908, in the pig, dog, and cat (N. America). Ward and Hirsch give the following differences between the spines of the three forms:--

_P. ringeri._ _P. westermanii._ _P. kellicotti._
Shape Chisel-shaped, Lancet-shaped, Chisel-shaped,
moderately heavy. very slender. heavy.
Distribution Circular rows, in Circular rows, Circular rows,
groups. in groups. singly.

Two other species, _P. rudis_, Diesing, 1850, in a Brazilian otter (_Lutra brasiliensis_) and _P. compactus_, Cobbold, 1859, in the Indian ichneumon, are but little known.

_Habitat._--Lungs, pleuræ, and especially the bronchi of man and dog. The alleged occurrence (of eggs) in other organs may be due to confusion with those of _Schistosoma japonicum_.

_Distribution._--China, Korea, and especially in Japan, where, according to Katsurada, there are no districts that are entirely free from pulmonary flukes. The _mountainous_ provinces of Okayama, Kumamoto, Nagano and Tokushima are the principal centres.

_Pathology._--The number present in the lung varies from two to twenty, about. Usually one cyst contains one worm, but in the dog each cyst contains two. The cysts admit the tip of the finger, and have a fibrous wall 1 mm. thick. They originate partly from dilatation of bronchi and bronchioles. Others arise from the inflammatory reaction of lung tissue into which the worms have wandered. The worms and their eggs cause bronchitis and peribronchitis, catarrhal, hæmorrhagic, or purulent, and areas of consolidation. Areas containing eggs in their centre resembling tubercle nodules are not uncommon, and extensive cirrhosis of the lung may be found. As a result of these changes, emphysema and bronchiectasis also occur.

As to the development, only the following details are known: that the eggs, which before segmentation of the ovum reach the open in the sputum and through being swallowed also in the fæces, develop in water into a miracidium ciliated all over, which hatches and swims about freely. According to Manson this takes place in four to six weeks.

Sub-family. *Opisthorchiinæ*, Looss, 1899.

Genus. *Opisthorchis*, R. Blanch., 1845.

Opisthorchiinæ with lobed testes. Laurer’s canal present. Parasitic
in the bile-ducts of mammals and birds.

*Opisthorchis felineus*, Riv., 1885.

Syn.: _Distoma conus_, Gurlt, 1831 (_nec_ Creplin, 1825); _Distoma
lanceolatum_, v. Sieb., 1836, v. Tright, 1889 (_nec_ Mehlis, 1825 =
_Fasciolo lanceolata_, Rud., 1803); _Distoma sibiricum_, Winogr.,
1892; _Distoma tenuicolle_, Mühl., 1896.

This parasite is yellowish-red in the fresh condition, and almost transparent. The body is flat, with a conical neck at the level of the ventral sucker marked by a shallow constriction; this, however, is only noticeable in fresh and somewhat contracted specimens. Posteriorly to the ventral sucker the lateral borders run fairly parallel; the posterior end is either pointed or rounded off. The length and breadth vary according to the contraction, being usually 8 to 11 mm. by 1·5 to 2 mm. The suckers are about one-fifth to one-sixth of the length of the body distant from each other, and of about equal size (0·23 to 0·25 mm.). The œsophagus is hardly any longer than the pharynx, which lies close behind the oral sucker; the intestinal cæca reach almost to the posterior border and are often filled with blood. The excretory pore is at the posterior extremity, and the excretory bladder forks in front of the anterior testis. The testes in the posterior fourth of the body lie obliquely one behind the other; the anterior one has four lobes, the posterior one five lobes; the ovary is in the median line transversely, simple or slightly lobed; behind it lies the large pear- or retort-shaped receptaculum seminis and Laurer’s canal. The uterus is in the median field. The vitellaria occupy the fairly broad lateral areas, in about the central third of the body, beginning behind the ventral sucker and terminating at about the level of the ovary; the acini are small and arranged in groups of seven to eight, separated by interstices. The genital pore is close in front of the ventral sucker. The eggs are oval with sharply defined operculum at the pointed pole, 30 µ, by 11 µ.

This species, which is frequently confused with others, inhabits
the gall-bladder and bile-ducts of the domestic cat especially;
but is also found in the dog, in the fox, and in the glutton
(_Gulo borealis_). It has been observed in France, Holland, North
Germany (being particularly frequent in East Prussia), in Russia,
Scandinavia, Siberia, Japan, Tonkin, Hungary, and Italy. The North
American form (from cats and _Canis latrans_) is a distinct species
(_Opisthorchis pseudofelineus_).

In man this species was first found by Winogradoff in Tomsk (nine cases), then by Kholodkowsky in a peasant from the neighbourhood of Petrograd who had travelled a great deal in Siberia, and finally by Askanazy in five persons who were natives of the East Prussian district of Heydekrug. In Tomsk, _Opisthorchis felineus_ is the most frequent parasite of man that comes under observation at _post mortem_ (6·45 per cent.), whereas _Tænia saginata_ has only been found in 3·2 per cent., Echinococcus in 2·4 per cent., _Ascaris lumbricoides_ in 1·6 per cent., and _Oxyuris vermicularis_ in 0·8 per cent. of the autopsies. In the district of Heydekrug, however, the species in question is also frequent, as in a few years five cases came to our knowledge (of which three were diagnosed by the discovery of the eggs in the fæces).

In none of Winogradoff’s nine cases had the death of the patient been caused direct by the parasites, yet more or less extensive changes in the liver were found in all of them; such as dilatation of the bile-ducts with inflammation and thickening of their walls, and foci of inflammation or atrophy in the liver substance; icterus was present five times and atrophy of the liver an equal number of times; ascites was observed three times, and in two cases, probably of recent date, the organ was enlarged. The number of parasites found fluctuated between a few and several hundreds.

In two of Askanazy’s cases, which he examined more closely, carcinoma which had developed at the places most invaded by flukes was found at the _post-mortem_, so that perhaps there may be grounds for the connection which the author seeks to establish between cancer of the liver and the changes induced by the parasites; these changes consist of numerous and even ramified proliferations of the epithelium of the biliary duct into the connective tissue, which is likewise proliferated. The number of worms found in one case amounted to over 100; in a second case, in which the parasites had also invaded the pancreatic duct, their number was even larger.

Winogradoff as well as Askanazy found isolated flukes in the intestine also.

Unfortunately, nothing much is known of the history of the development of _Opisthorchis felineus_; we only know that when deposited the eggs already contain a ciliated miracidium, which, however, according to my experience, does not hatch out in water, but only after the entry of the eggs into the intestine of young _Limnæus stagnalis_; no further development, however, occurs. Winogradoff states that he has seen the miracidia hatch after the eggs had been kept in water for a month at 37° C.; and has even observed free miracidia in the bile of man and of a dog respectively. Although the whole post-embryonal development of the cat fluke remains yet to be investigated, Askanazy by a series of experiments on cats and dogs has discovered the mode of infection. The intermediate hosts are fish, and mainly the ide, in this country called Tapar (_Idus melanotus_, H. and Kr.), and of subsidiary importance the roach (_Leuciscus rutilus_). Both species of fish as well as others are readily eaten raw by man on the Courland lagoon (Baltic). It is, moreover, significant that those persons whom Askanazy found infected with the cat fluke were also infected with _Dibothriocephalus latus_, the intermediate host of which is also fish (Lota sp., Esox sp., Perca sp.).

In one of his nine cases Winogradoff also saw a small fluke covered all over with spines, which he conjectured to be the young stage of _Opisthorchis felineus_; as, however, according to my experience, this species, even in smaller specimens, is always without spines, the above hypothesis cannot be accepted. It is much more probable that one of the other species that also invade the liver of cats may accidentally be introduced into man; we know, in fact, that _Metorchis albidus_, Braun, and _Metorchis truncatus_, Rud., are both covered with spines. As, however, the spines of the first-named species are rather apt to fall off, and also as it possesses a different shape (spatula-shaped), it may be assumed that probably Winogradoff had found _Metorchis truncatus_, Rud., 1819, in his patient.

Genus. *Paropisthorchis*, Stephens, 1912.

Structure as in Opisthorchis, except that the ventral sucker and
genital pore occur on the apex of a process or pedicle projecting
from the anterior portion of the body. This process is about 1/2 mm.
long, and is retractile.

*Paropisthorchis caninus*, Barker, 1912.

Syn.: _Distoma conjunctum_, Lewis and Cunningham, 1872; _Opisthorchis
noverca_, M. Braun, 1903 (_pro parte_); _Opisthorchis caninus_,
Barker, 1912 (?).

Length varies from 2·75 to 5·75 mm. in preserved specimens, average 3·6 to 5·2 mm. Body uniformly spinose, though as a rule spines are not present on the pedicle. Body slightly concavo-convex, the concavity being ventral. Oral sucker 0·28 mm. Pharynx 0·224 by 0·184 mm. Œsophagus 0·04 mm. Ventral sucker 0·176 mm. in diameter. Pedicle about 1/2 mm. long, may be completely retracted.

_Genital Pore_--opens on the apex of the pedicle in front of the ventral sucker. Its exact position varies with the state of contraction of the parts. In certain cases it actually opens within the cuticular border of the sucker, in other cases it opens externally to the sucker and anterior to it. The opening is covered with scales. The vas deferens and uterus run alongside one another until they merge near the apex of the pedicle into a common sinus.

_Vitellaria_--consist of eight acini on each side, extending from slightly behind the base of the pedicle to the anterior border of the ovary, or as far back as a line separating the posterior border of the ovary from the anterior border of the anterior testis.

_Testes._--Anterior testis 0·496 by 0·44 mm.; posterior testis 0·52 by 0·48 mm., usually ovoid, though both may be regularly lobed. The anterior testis is usually on the left side.

_Ovary_--multilobular, the lobes 6 to 8 being irregular in size and shape.

_Shell Gland_--extensive and diffuse, occupying an area which approximately corresponds with the loop of the transverse vitelline ducts.

_Seminal Receptacle_--globular, to the right of and dorsal to the posterior lobe of the ovary.

_Laurer’s Canal_--generally runs from the end of the receptacle with a single curve medially and backwards.

_Uterine Coils_--form loosely packed transverse coils terminating slightly in front of the level of the first vitelline acini. From here the uterus passes forwards into the pedicle to the left and ventral to the seminal vesicle.

_Seminal Vesicle_--commences about the level of the first vitelline acini. The coils displace the uterus ventrally and to the left. In the pedicle the vesicle diminishes in extent and lies in its dorsal (anterior) side.

_Habitat._--Liver of pariah dogs, India. In North-Western Provinces about 40 per cent. are infected. This fluke appears to be different from _Amphimerus_ (_Opisthorchis_) _noverca_ in man, as the latter has not the pedicle on the summit of which lie the sucker and common genital pore.

Genus. *Amphimerus*, Barker, 1912 (?).

Structure as in Opisthorchis, except that the vitellaria are
separated into two portions, an ant-ovarial and a post-ovarial.

*Amphimerus noverca*, Barker, 1912 (?).

Syn.: _Distomum conjunctum_, McConnell, 1876 (_nec_ Cobbold, 1859);
_Opisthorchis noverca_, M. Braun, 1903 _pro parte_.

At the autopsy of two Mahommedans who died in Calcutta, McConnell found a large number of Distomata in the thickened and dilated bile-ducts. The worms were lancet-shaped, covered with spines, and measured 9·5 to 12·7 mm. in length and 2·5 mm. in breadth. The two suckers lie very close to one another, the anterior one being larger than the ventral; the genital pore opens immediately in front of the ventral sucker; pharynx spherical; intestinal cæca extending far back. At the commencement of the posterior third of the body the two testes, somewhat apart, the anterior one roundish, the posterior one distinctly lobed. The transverse and slightly lobed ovary in front of the bifurcation of the *Y*-shaped excretory bladder, whence the uterus, in convolutions barely spreading beyond the central field, extends to the pore; the vitellaria in the lateral areas commence behind the ventral sucker and extend to the testes. Cirrus pouch absent. Eggs oval, 34 µ by 21 µ.

Genus. *Clonorchis*, Looss, 1907.

Structure as in Opisthorchis, distinguished, however, by the branched
testes situated one behind the other, the branches of which ventrally
encroach upon the gut forks; dorsal to the testes the *S*-shaped
excretory bladder, the main branches of which, arising at the level
of the bifurcation of the gut, open into the bladder below its
anterior end. Parasitic in the bile-ducts of mammals and man.

(Syn.: _Distomum conjunctum_, Cobb., _nec_ Lew. and Cunn., _nec_ McConn.): from _Canis fulvus_. _Vs._, ventral sucker; _I._, intestine; _Vsc._ vitellaria; _Ex._, excretory bladder; _T._, testes; _O._, ovary; _Ms._, oral sucker; _Ph._, pharynx; _Ut._, uterus. (After Cobbold.)]

[272] This species from _Canis fulvus_ was for long thought to be the same as that here described as _Amphimerus noverca_. It probably does not belong to the genus Metorchis.

*Clonorchis sinensis*, Cobbold, 1875.

Syn.: _Distoma sinense_, Cobbold, 1875; _Distoma spathulatum_, R.
Leuckart, 1876 (_nec_ Rudolphi, 1819); _Distoma hepatis innocuum_,
Baelz, 1883.

In shape resembles _Opisthorchis felineus_, 13 to 19 mm. long, 3 to 4 mm. broad, at the beginning of sexual maturity 12 to 13 mm. long, 2·5 to 3 mm. broad. Oral sticker 0·58 to 0·62 mm., ventral sucker 0·45 to 0·49 mm. in transverse diameter. In the parenchyma numerous yellowish or brownish granules, especially behind the oral sucker and at the posterior end. Testicular branches very long, in the anterior testis often four, in the posterior testis five branches. Ovary generally with three large lobes and a smaller lobe. Vitellaria not always symmetrical, generally extending laterally from the ventral sucker to the ovary, interrupted in parts.

Eggs 26 µ to 30 µ by 15 µ to 17 µ. Average 29 µ by 16 µ.

This (?) species was discovered in 1874 by McConnell, in Calcutta, in the bile-ducts of a Chinaman who died shortly after being admitted into hospital.

_Habitat._--Bile-ducts of man, dog and cat.

_Distribution._--Especially in China, apparently rare in Japan.

*Clonorchis endemicus*, Baelz, 1883.

Syn.: _Distoma sinense_ s. _spathulatum p.p._; _Distoma hepatis
endemicum_ s. _perniciosum_, Baelz, 1883; _Distoma japonicum_, R.
Blanchard, 1886.

Very similar to the previous species and consequently generally confused with it. Length between 6 and 13 mm., width varying between 1·8 and 2·6 mm. Oral sucker 0·37 to 0·5 mm., usually 0·43 to 0·45 mm. in transverse diameter; ventral sucker 0·33 to 0·45 mm., usually 0·37 to 0·40 mm. No pigment in parenchyma; anterior testis with four, posterior testis with five branches. Vitellaria continuous, ova 26 µ by 13 µ to 16 µ.

_Habitat._--Bile-ducts of man, dog, cat and pig.

_Distribution._--This species occurs very frequently in man, in certain districts of Japan, especially in the province of Okayama, Central Japan, in particular localities of which above 60 per cent. of the population are infected. The worms are sometimes found in enormous numbers in the liver (upwards of 4,000), also in the pancreas and rarely in the duodenum. It is common in Tonkin and Indo-China. Léger in Tonkin found 50 per cent. of people apparently in normal health infected, so that probably symptoms only arise when the infection is intense. [The exact distribution of these two species is, however, not precisely defined at present, as commonly no distinction is made between them.--J. W. W. S.]

Verdun and Bruyant deny, in opposition to Looss, the possibility of being able to distinguish within the genus Clonorchis the two species described, but they admit the justification for the new genus. They also report the occurrence of _Opisthorchis felineus_ in man in Tonkin (_Compt. Rend. Soc. de Biol._, lxii, 1907).

_Pathology._--Both species of Clonorchis give rise to grave symptoms. The liver is generally enlarged, though when the infection has lasted some time it begins to contract. The surface of the organ is studded with white vesicles, and on cutting into it one sees numerous cavities with thickened walls (distended bile-ducts) filled with a brownish fluid containing innumerable eggs, which cause its colour. Microscopically, the epithelium of the bile-ducts is either (1) entirely destroyed, or (2) actively proliferates, forming an adenomatous outgrowth. Occasionally this proliferation is not limited by the wall of the bile-duct but penetrates it and leads to a growth of numerous new ducts, forming a malignant biliary adenoma. The bile-ducts have their connective tissue wall greatly sclerosed. These fuse with one another, forming areas of sclerosis devoid of liver tissue. As a result of these changes the liver cells atrophy and undergo fatty pigmentary and granular degeneration. Besides these changes, due probably to the toxic action of the flukes, mechanical obstruction due to the actual plugging of the ducts by the flukes causes retention of bile and icterus, and through pressure on veins, ascites and hypertrophy of the spleen.

To what extent blood or bile respectively forms the food of the flukes is uncertain.

_Life-history._--(Kobayashi, 1911, _Mitteilungen aus dem kaiserlichen Institut für Infektions-Krankheiten zu Tokio_, pp. 58–62.)

It results from the work of Kobayashi in Japan that fresh-water fish form the _second_ intermediate host for _Clonorchis endemicus_. He fed cats with encysted flukes (cercariæ) from various fish and easily succeeded in infecting them, _e.g._ a kitten, proved to be uninfected by repeated examination of its fæces, was fed on infected fish; a month later innumerable flukes were found in the bile-ducts, gall-bladder, pancreas and even in the duodenum. The fish infected were _Leucogobis güntheri_, _Pseudorasbora parva_, and to a less extent _Acheclognathus lanceolata_, _Acheclognathus limbata_, _Paracheclognathus rhombea_, _Pseudoperilampus typus_, _Abbottina psegma_, _Biwia zezera_ and _Sarcocheilichthys variegatus_. The cysts occur throughout the muscles and subcutaneous tissue of the fish. Length 0·13 mm., breadth 0·1 mm. The cercaria lies folded in the cyst, length 0·5 mm. breadth 0·1 mm. It tapers posteriorly. Skin at first covered with fine spines, disappearing as they grow older. Body dotted with fine pigment.

The _first_ intermediate host is still unknown.

Sub-family. *Metorchiinæ*, Lühe, 1909.

Genus. *Metorchis*, Looss, 1899, emend. auctor.

Hind end rounded. Gut forks reach extreme end. Testes only slightly
lobed, filling the hind end.

*Metorchis truncatus*, Rud., 1819.

This species, which attains a length of 2 mm., is slender and conical, the anterior end is pointed and the posterior truncated, and provided with a muscular tuberosity that resembles a terminal sucker; for this reason the discoverer of the species (Rudolphi) classed it with the Amphistomes. The cuticle in the young, as well as in the adult specimens, is entirely and closely covered with spines. Suckers about equal in size (0·134 to 0·172 mm.); the ventral sticker lies somewhat in front of the middle of the body. The pharynx is small (0·09 mm.), the œsophagus minute, the intestinal cæca reach to the posterior extremity. Between them, and in front of their blind ends, lie the two elliptical testes, one generally a little in front of the other. In front of them, either in the median line or somewhat laterally, the spheroidal ovary is situated; in front, again, is the uterus, the coils of which usually extend beyond the median field. The vitellaria are at the sides of the central third of the body, thus commencing in front of the ventral sucker; cirrus pouch absent; the genital pore is close in front of the acetabulum. The excretory pore is terminal (?). Eggs 29 µ by 11 µ.

_Metorchis truncatus_ lives in the bile-ducts of the seal, cat, dog, fox, and glutton (_Gulo borealis_). The source of infection is unknown, although one would suspect fish. Askanazy did not succeed in getting this fluke in his feeding experiments, but another species, _Metorchis albidus_, not uncommon in cats by feeding them on roach (_Leuciscus rutilus_).

Family. *Heterophyiidæ*, Odhner, 1914.

Genus. *Heterophyes*, Cobbold, 1866.

Syn.: _Cotylogonimus_, Lühe, 1899; _Cænogonimus_, Looss, 1899.

No crown of spines on head. Body divided into a narrow, movable,
anterior part (neck), and a broader, less movable, posterior
portion, which contains the genitalia. The suckers separated from
one another by a space equal to half the length of the body or more;
the pharynx is close behind the oral sucker; the œsophagus is long;
the intestinal cæca extend to the posterior border; the genital pore
is placed laterally, and behind the ventral sucker. Genital sucker
provided with a circlet of chitinous rodlets, shaped like stags’
horns. The testes are at the posterior end, the ovary in a median
position in front of them. Laurer’s canal with receptaculum seminis
present; the small vitellaria are at the sides of the posterior part
of the body. Parasitic in the intestine of mammals and birds.

*Heterophyes heterophyes*, v. Sieb., 1852.

Syn.: _Distomum heterophyes_, v. Siebold, 1852; _Heterophyes
ægyptica_, Cobbold, 1866; _Mesogonimus heterophyes_, Railliet, 1890;
_Cœnogonimus heterophyes_, Looss 1900; _Cotylogonimus heterophyes_,
Braun, 1901.

Length up to 2 mm., breadth 0·4 mm.; the neck not sharply defined; in life it stretches to double the length of the hind body. The scales are rectangular, 5 µ to 6 µ by 4 µ, their posterior margin serrate with seven to nine teeth. Cuticular glands are numerous on the ventral surface, especially in the fore part of the body, and partly discharge at the anterior border of the oral sucker. The oral sucker is 0·09 mm., the ventral sucker 0·23 mm. in diameter; the pharynx measures 0·05 to 0·07 mm. in length; the œsophagus is about three times as long; posteriorly the intestinal cæca are directed one towards the other and terminate beside the excretory bladder. Close in front of the posterior ends of the intestinal branches are the two elliptical testes, which are not exactly on the same level. In the middle in front of them is the receptaculum seminis, and in front of the latter lies the spherical or elliptical ovary. The two vasa efferentia unite to form the vas deferens, which after a short course passes over into the angularly bent seminal vesicle; after the entry of the prostatic glands it becomes united with the metraterm (vagina), and the common duct opens into the genital sucker. The latter is somewhat smaller than the ventral sucker, lateral to and close (0·15 mm.) behind it, and bears a not entirely closed ring of from seventy-five to eighty chitinous rods (20 µ in length). The vitellaria on either side consist of about fourteen acini. The uterus is spread almost throughout the entire posterior part of the body. The eggs have thick shells with a knob resembling that of Clonorchis eggs but not so prominent, and measure 30 µ by 17 µ; they contain a completely ciliated miracidium with a rudimentary intestinal sac.

This species was discovered in 1851 by Bilharz in the intestine of a boy who died in Cairo; a second case was only found in 1891 and published by R. Blanchard, so that it appeared as if the species were very scarce. According to Looss, this is, however, not the case, but the species easily escapes notice on account of its small size. Looss found it in Alexandria twice in nine autopsies, and once in Cairo, and has recently stated that in man “it is not at all uncommon to meet with the parasite in cadavers, and the eggs of the worm in the stools of the patients.” Leiper records one case from Japan and one from China. The parasites occupy the middle third of the small intestine, and even when present in large numbers appear to be harmless.

This small species, according to Looss, frequently occurs in Egyptian dogs, less so in cats, and has also been found in the fox, as well as once in _Milvus parasiticus_; Janson also reports this species from the intestine of the dog in Japan.

*Metagonimus*, Katsurada, 1913; Yokogawa, Leiper, 1913.

Resembles in general structure Heterophyes. In the arrangement of its ventral genital suckers resembles but differs from that of Tocotrema,[273] Looss. The ventral and genital suckers lie laterally and on the right.

[273] In the genus Tocotrema the common genital duct opens into the ventral sucker.

*Metagonimus yokogawai.* Katsurada, 1913.

Syn.: _Yokogawa yokogawai_, Leiper, 1913.

One to 1·5 mm. long, seldom 2·5 mm., and 0·4 to 0·7 mm. broad; elliptical in shape. The body is thickly covered with nail-shaped spines about 10 µ long. Oral sucker 77 µ, to 85 µ in diameter. Ventral sucker characteristic and peculiar 0·12 to 0·14 mm. by 0·08 to 1 mm. It is a sac-like organ placed deeply in the body, but does not open as in other flukes on the ventral surface. Testes elliptical, not quite symmetrically placed at the hind end of the body. Vesicula seminalis retort-shaped, situated transversely, internal to the ventral sucker. Pars prostatica present. Ejaculatory duct opens with the uterus into a genital sinus, which, together with the internal opening of the ventral sucker, opens into a pit at the front of the ventral sucker. The opening of the genital sinus and that of the ventral sucker are furnished with a complex muscular apparatus. Ovary spherical, 0·12 to 0·13 mm. in diameter, lies in the middle of the hind body. Receptaculum seminis and Laurer’s canal present. Vitellaria in the hind half of the body, consisting of about ten acini on each side. Shell gland to the left of the ovary. Uterus forms three to four transverse coils. Eggs elliptical, double contoured, yellowish-brown in colour. There is no shoulder below the operculum as in the eggs of _Cl. sinensis_. At the rounder end there is a thickening or knob different from the spine-like or hook-like process seen in _Cl. sinensis_. Dimensions 28 µ by 16 µ.

_Habitat._--Mainly in upper or middle portion of jejunum, rarely in cæcum. They penetrate deep into the mucosa, but not into the submucosa, and _post mortem_ appear as a number of small brown points. They frequently occur in the solitary glands, which they destroy. They cause chronic catarrh of the gut. Parasitic in man and mammals.

_Geographical Distribution._--Japan.

_Life-history._--The cercarial stage occurs in a trout (_Plecoglossus altivelis_) and seldom in Crassius sp. and Cyprinus sp. Infection takes place through the eating of the fish raw. Seven to sixteen days later eggs appear in the fæces (of dog).

Family. *Dicrocœliidæ*, Odhner, 1910.

Genus. *Dicrocœlium*, Dujardin.

_Dicrocœliidæ_, with leaf-shaped bodies, pointed posteriorly and
anteriorly. Greatest width behind the mid-line. Vitellaria double.
The testes smooth or indented, lying symmetrically or obliquely
beside or behind the ventral sucker. The ovary approaches the median
line behind one testis. Parasitic in the liver and gall-bladder
(rarely in the intestine) of members of all classes of vertebrate
animals--by preference in birds and mammals.

*Dicrocœlium dendriticum*, Rud., 1819.

Syn.: _Dicrocœlium lanceatum_, Stil. and Hass., 1896; _Fasciola
lanceolata_, Rud., 1803 (_nec_ Schrank, 1790); _Distomum
lanceolatum_, Mehlis, 1825; _Dicrocœlium lanceolatum_, Dujardin, 1845.

Body lancet-shaped, narrowing especially at the anterior extremity; length 8 to 10 mm., breadth 1·5 to 2·5 mm., the greatest breadth usually behind the middle of the body. Suckers distant from each other by about one-fifth the length of the body; oral sucker about 0·5 mm., ventral sucker about 0·6 mm. Pharynx globular, adjoining the oral sucker; œsophagus 0·6 mm. in length; intestinal cæca reach to four-fifths of the body length. Genital pore at the level of the bifurcation of the intestine; cirrus pouch small and slender. The large, slightly lobed testes lie obliquely one behind the other behind the ventral sucker; the ovary, which is considerably smaller, is placed behind the posterior one; the vitellaria, commencing at the level of the posterior testis, terminate far before the cæca. The uterus, situated behind the ovary, extends throughout the posterior end, not confined to the central field, but overlapping the lateral fields with its transverse coils; at the posterior edge of the body it turns back again and winds forwards to the ovary in transverse loops, then between the testes, and finally, dorsal to the ventral sucker, terminates in the genital pore. The thick-shelled eggs when young are yellowish, when older dark brown. They measure 38 µ to 45 µ by 22 µ to 30 µ. They contain an oval or roundish miracidium, only the anterior part of which is ciliated, and which possesses a rudimentary intestinal sac with a boring spine. The miracidia do not hatch out in water spontaneously, but, according to Leuckart, in the intestines of slugs (_Limax_, _Avion_), but they do not develop either in these (slugs) or in water-snails.

The lancet fluke inhabits the biliary duct of herbivorous and omnivorous mammals (sheep, ox, goat, ass, horse, deer, hare, rabbit, pig), and is often found associated with the liver fluke; it is not, however, so common nor so widely disseminated, nevertheless, it has been met with outside of Europe, namely, in Algeria, Egypt, Siberia, Turkestan, and North and South America.

In man it is still more uncommon than the liver fluke, and has hitherto only been observed seven times (Germany, Bohemia, Italy, France, and Egypt); it may, however, have occurred more frequently, and have been overlooked, as in slight infections it produces no special symptoms.

The intermediate host is still unknown. Leuckart for some time held the opinion that small species of _Planorbis_ from fresh water, which contain encysted Distomata, were to blame, and he supported his views by a feeding experiment which seemingly yielded positive results; this, however, is not definitely proved. Piana’s statement that small land snails are the intermediate hosts has also not been proved.

Family. *Echinostomidæ*, Looss, 1902.

Sub-family. *Echinostominæ*, Looss, 1899.

Genus. *Echinostoma*, Rud. 1809; Dietz, 1910.

Fore-body not bulging. Greatest width at or behind the ventral sucker. Oral sucker not atrophied. Collar kidney-shaped with a double dorsally unbroken row of spines, terminating in four to five angle spines. The border spines of the aboral series not larger than the oral. Skin spined or smooth. Body elongated. Uterus long with numerous transverse coils. Ventral sucker in the anterior quarter of body. Cirrus sac small, almost completely in front of the ventral sucker. Testes round or oval, smooth incurved or lobed, in the hinder half of body. Ovary median or lateral in front of testes. Vitellaria from hinder margin of ventral sucker to end of body. Eggs oval, 84 µ to 126 µ by 48 µ to 82 µ.

The spines placed most ventrally, or those placed most medially on ventral surface, are from differences of position or form termed “angle” spines, the rest “border” spines.

_Type._--_Echinostoma echinatum_, Rud.

*Echinostoma ilocanum*, Garrison, 1908.

Length 4 to 5 mm., breadth 1 to 1·35 mm., thickness 0·5 to 0·6 mm. The circum-oral disc 0·3 mm. broad, separated by a shallow groove from the body. Crown of forty-nine spines and five to six angle spines on each side continuous with an irregularly alternating series of fourteen spines on the dorsum. Largest spines are 34 µ long, 8 µ thick at the base. The remainder of the dorsal spines are 24 µ by 6 µ. Skin thickly covered with scales on the margins of the body as far back as the level of the hind testis. Oral sucker, 0·18 mm.; ventral sucker, 0·4 to 0·46 mm. Its anterior border about 0·07 mm. from the anterior end. Pharynx 0·17 mm. long, 0·11 mm. broad. Testes about mid-line of the body, much lobed; the lobes of the anterior testis run transversely, while the axis of the posterior testis is longitudinal, as often occurs in the _Echinostomidæ_. Cirrus sac reaches to the centre of the ventral sucker. Ovary transversely oval in front of the testes. Vitellaria commence about half-way between the ventral sucker and ovary and extend to the posterior end. Eggs numerous, 92 µ to 114 µ by 53 µ to 82 µ.

_Average._--99·5 µ by 56 µ.

_Habitat._--Gut of man (Filipinos), Philippine Islands.

*Echinostoma malayanum*, Leiper, 1911.

Twelve millimetres long, 3 mm. broad, 1·3 mm. thick. Ends bluntly rounded. At the anterior end a ventral furrow on either side, one-third the width of the body, marking off the circum-oral collar. Along its edge is a row of forty-three spines extending across the middle line dorsally but not ventrally. The spines vary in size from 0·07 mm. in length (ventrally) to 0·05 to 0·016 mm. (dorsally). Cuticular spines also exist on the ventral side as far back as posterior end of body, but dorsally limited to a triangular area ending in front of the ventral sucker. Oral sucker 0·07 mm. thick, occupying the middle third of the circum-oral disc; pharynx 0·25 mm. in diameter; œsophagus 0·04 mm. long; gut cæca simple, extending to end of body; ventral sucker 0·9 mm. long by 0·75 mm. broad by 0·7 mm. deep; wall about 0·25 mm. thick. The sucker is inclined at an angle of 40° to the ventral surface. Testes lobed, one behind the other, behind the ventral sucker. Cirrus pouch well developed, reaching to the posterior edge of the sucker. Genital pore in the angle between neck and anterior lip of ventral sucker. Ovary smooth, 0·3 mm. in diameter, 0·85 mm. behind ventral sucker. Vitellaria very numerous, extending from posterior margin of sucker to posterior end of body, where they intermingle. Eggs few in number, brown and large.

_Habitat._--Gut of man (Tamils), Malay States.

Sub-family. *Himasthlinæ*, Odhner, 1910.

Genus. *Artyfechinostomum*, Clayton-Lane, 1915.

Crown of thirty-nine spines, continuous over dorsum. Two corner spines long. Vitellaria extend from posterior margin of sucker to posterior end of fluke. Eggs without filament. [Although the possession of strong rose-thorn hooks is given by Odhner as a sub-family characteristic, yet in this genus assigned to this sub-family they have not been seen.--J. W. W. S.]

*Artyfechinostomum sufrartyfex*, Clayton-Lane, 1915.

Spirit specimens: 9 by 2·5 by 0·8 mm. thick. Ventral sucker conspicuous, 1 mm. in diameter. Cirrus sac 2 mm. long. Testes lobed, about 1·5 mm. in diameter. Posterior border of posterior testes 1 mm. from posterior end. Vitellaria meet posteriorly behind the posterior testis.

Family. *Schistosomidæ*, Looss, 1899.

Genus. *Schistosoma*, Weinl, 1858.

Syn.: _Gynæcophorus_, Dies., 1858; _Bilharzia_, Cobb., 1859;
_Thecosoma_, Moq. Tandon, 1860.