Chapter I: II. III. IV. V (1)

_M. europæus_, Atlantic City:
Left 2 6 6 3+ 3+
Right 2 7 6 4(+1?) 4
_M. bidens_:
Landenæs 1 6(5) 5 4 3
Fæø 1 6 5 4 3
Udsire 1 6 6 5 4

In _M. europæus_ the metacarpal of the third digit is much constricted in the middle. The shaft of the ulna is straight. Except in these particulars and the relatively small size of the whole pectoral limb, the latter appears not to differ materially from that of _M. bidens_. As shown above, the first digit in _M. bidens_ consists of the metacarpal bone only, while in _M. europæus_ a phalange is also present.

_Dimensions of the skeleton of the Atlantic City specimen of M.
europæus, No. 23846, U.S.N.M._

mm.
Length of the seven cervical vertebræ[a] 94
Length of first, second, and third cervical 45
vertebræ[a]
Atlas:
Greatest breadth 156
Greatest height 103
Height of neural canal 36
Greatest breadth across anterior articular 96
facets
Axis, greatest breadth 144
Seventh cervical vertebra:
Greatest breadth 80
Greatest height without inferior process 117
Greatest length of centrum 14
Greatest height of neural canal 49
First thoracic vertebra:
Greatest height 151
Greatest breadth 136
Height of centrum 37
Length of centrum 21
Breadth of centrum (articular surface) 48
Height of neural spine 61
Height of neural canal 53
Seventh thoracic vertebra:
Greatest height 246
Greatest breadth 116
Height of centrum 35
Length of centrum 69
Breadth of centrum 46
Breadth between transverse processes 66
Eighth thoracic vertebra:
Greatest height 246
Greatest breadth (between transverse processes) 142
Height of centrum 39
Length of centrum 73
Breadth of centrum 47
First lumbar vertebra:
Greatest height 263
Greatest breadth (between transverse processes) 215
Height of centrum (anterior) 43
Length of centrum 83
Breadth of centrum 53
First caudal vertebra:
Greatest height 263
Greatest breadth (between transverse processes) 207
Height of centrum (anterior) 65
Length of centrum 113
Breadth of centrum 67
Seventh caudal vertebra:
Greatest height 153
Greatest breadth 87
Height of centrum (without hypapophysis) 66
Length of centrum 84
Breadth of centrum 70
Length of last 10 caudal vertebræ 285
Sternum:
Total length 404
Length of manubrium 165
Greatest breadth of manubrium 134
Depth of anterior notch of manubrium 37
Scapula:
Length 247
Depth 161
Length of acromion [b]44
Length of coracoid 59
Humerus, length 107
Radius, length 110
Ulna, length 100
Pelvic bones, length 51

[a] Placed in contact.
[b] From the inside, without the cartilaginous tip.

HISTORY OF THE ATLANTIC CITY SPECIMEN.

Regarding the finding of the Atlantic City specimen and its exterior and gross anatomy, nothing has been published except brief references by Sir William Turner in 1889[25] and Dr. Glover M. Allen in 1906,[26] taken from a newspaper report of a communication made by myself before the Biological Society of Washington in 1889. On that account a somewhat detailed statement regarding it will be made in this place.

This individual (Pl. 41, figs. 1, 2) was a male, 12½ feet long. It was observed by the crew of life-saving station No. 28, near Atlantic City, New Jersey, on the afternoon of March 28, 1889. It had come inside the bar which skirts the coast at this point, and was apparently unable to find its way out. It was captured with some difficulty, after being wounded in the throat, and was dragged up on the beach near the station. Later in the day it was carried to the skating rink of Messrs. Johnson & McShea, at Atlantic City, where it was exhibited until Monday, April 1. On the next morning it was sent by express to Washington.

I examined it for the first time in Atlantic City on March 29. It was then lying on the floor of the skating rink in such a position that the under surfaces were concealed, and, as the teeth were not visible, I mistook it for a female. Upon its arrival in Washington, however, where it could be examined under more favorable circumstances, it proved to be a male. The following measurements were taken from the fresh specimen:

_External dimensions of a specimen of M. europæus from Atlantic City,
New Jersey._

Ft. in.
Total length (in a straight line) 12 6
Tip of beak to base of dorsal fin (along the back) 7 6½
Tip of beak to base of pectoral fin (along the back) 2 11
Length of pectoral fin along center 11
Greatest breadth of pectoral fin 3¾
Height of dorsal fin (in a straight line) 6
Length of base of dorsal fin 1 2
Breadth of flukes (tip to tip) 2 11
Depth of tail 14 inches in front of posterior margin 8¼
of flukes
Tip of beak to angle of mouth 9¾
Tip of beak to eye 1 8¼
Length of eye 1
Breadth of blowhole 4
Tip of beak to right angle of blowhole 1 6½

EXTERNAL FORM AND COLOR.

The general form was slender and elongate. The beak sloped gradually from its extremity to the forehead, and there was no constriction separating the beak from the remainder of the head. Behind the blowhole, the outline of the back commenced at a higher level, but immediately curved slightly downward, indicating the position of the neck. The line then rose gradually until the anterior base of the dorsal fin was reached. Behind the fin the outline sloped downward gradually to the flukes.

The dorsal fin was relatively small, falcate, and obtusely terminated. The distance in front of its anterior base was three-fifths of the total length. Its posterior margin was continuous with the ridge of the back, which extended to the flukes and terminated abruptly a little anterior to the middle point of the antero-posterior breadth of the flukes. In front of the fin the back was rounded.

The pectoral fins were small and were placed low down on the sides. Their anterior base was as far removed from the eye (in a straight line) as the eye was from the extremity of the beak. Their shape was somewhat different from that of the flippers of _M. bidens_ figured by Sir William Turner.[27] Their anterior margin was nearly straight throughout; the extremity was evenly and distinctly rounded off. The posterior margin was slightly convex in the distal half and straight proximally.

The conformation of the region of the axilla was quite peculiar. The hard integument of the posterior margin of the flipper was continued proximally inward and forward to a point near the head of the humerus. The triangular area between this stiff edge and the side of the body was occupied by a thin, soft, wrinkled skin, in the middle of which the olecranon could be felt. On the side of the body this soft integument occupied an area nearly as large as the flipper, the underlying thick layer of blubber ending abruptly, especially below. A depression was thus formed in which the flippers could be placed so as to be almost in the same general plane with surrounding surfaces of the body. They are probably so placed when the animal is swimming.

The flukes had the general lunate form common to all species of the order. The posterior margin is not divided in the center. Its middle third was convex; its lateral thirds concave. In these and other respects the shape of the flukes agreed closely with Sir William Turner’s excellent figure of _M. bidens_.[28] The antero-posterior breadth of the flukes was, however, somewhat greater in proportion to their transverse breadth than is indicated in this figure. The caudal peduncle terminated above at a point 6½ inches in front of the posterior margin of the flukes. On this margin were situated three star-shaped white scars, which appeared to mark the points of attachment of crustacean parasites.

The margins of the upper jaw were very obtuse posteriorly, the rostrum being covered with a layer of blubber of gradually increasing thickness. A depression bounded by gradually converging lines extended 4¼ inches back of the angle of the mouth.

The inferior surface of the bony palate extended below the level of the lips, and the sides of the former were visible upon looking into the mouth laterally.

The blowhole was large and somewhat unsymmetrically placed, the right angle being the more anterior. The concavity was forward.

The eye was situated a little below the line of the mouth and 20¼ inches from the extremity of the snout.

The external opening of the ear was 2⅞ inches behind the posterior angle of the eye, and a little below the line of the lower eyelid.

The two throat-furrows were of unequal length. The left furrow was 6¾ inches long, and its anterior end was distant 8⅝ inches from the extremity of the jaw. The right furrow did not extend quite so far forward, and was 7⅜ inches long.

The furrows converged posteriorly; they were separated by an interval of ⅝ inches anteriorly and 5⅛ inches posteriorly. Between the anterior ends of the main furrows was a small one, about an inch long, but it is doubtful whether this was a natural fissure. I did not observe it when the whale was in Atlantic City.

The natural color of the specimen had largely disappeared before I examined it, but Captain Gaskell and others who saw it while still fresh agreed that it was very dark slate-gray on the back, lighter on the sides, and whitish on the belly. I observed that a broad area between the pectoral fins was slate-gray, and contrasted with the white of the throat and belly. The whitish color ended somewhat abruptly and irregularly at the anus, and the flukes, as well as the pectoral and dorsal fins, were probably very dark slate-gray, or blackish, when fresh.

The epidermis was exceedingly smooth and glossy throughout.

The tongue was purplish-white. The roof of the mouth was black, except at the posterior end, where there was an irregular area of pinkish-white.

The integument of the roof of the mouth was smooth and shining. Its surface was convex at the extremity of the beak, but the central portion was concave, while at the posterior end it was again raised into a rounded pad. In these respects the shape of the integuments coincided with that of the underlying maxillæ, upon which they were closely fitted. The sides were rounded, and a shallow groove intervened between them and the lips. This groove was continued around the roof of the mouth behind, and formed a demarcation between this part and the œsophagus.

The tip of the tongue was 7½ inches from the extremity of the jaw. It was oval in outline, the extremity is obtuse, and it was entirely bound down. The margin was entire, and not crenulate, as in many dolphins.

Dorsal and ventral views of the stomach are shown in Pl. 40, figs. 1 and 2; a dorsal view of the lungs in Pl. 13, fig. 5; and of the perineum in Pl. 40, fig. 3. A description of the gross anatomy is reserved for a subsequent paper.

The external dimensions of the Atlantic City specimen of _M. europæus_ are given in the following table, together with those of nine European specimens of _M. bidens_ taken from various authors, and assembled here for purposes of comparison. The dimensions of the Annisquam specimen which, as already explained (p. 9), represents a third species, are also added.

_External dimensions of Mesoplodon europæus, M. bidens, and M.
densirostris._

Column headings:
_M. europæus._
C: Atlantic City, 1889, U.S.N.M. male, imm.
_M. bidens._
D: Brodie House, Scotland, 1800, (Sowerby), male, adult.[a]
E: Overstrand, England, 1892, (Southwell), female, adult.
F: Dalgety, Scotland, 1888, (Turner), male.
G: Hillville, Kerry, Ireland, 1864, (Andrews), male (?).
H: Hevringholm, Denmark, 1880, (Reinhardt), female, adult.
I: Rugsund, Norway, 1901, (Grieg), male, adult.
J: Saltö, Sweden, 1885, (Aurivillius), male, young.
K: Landenæs, Norway, 1895, (Grieg), male.
L: Ostend, Belgium, 1835, (Dumortier), female, young.
_M. densirostris?_
M: Annisquam, Mass., 1898, (Allen), female.

Measurements. C D E F G H I J K L M mm. mm. mm. mm. mm. mm. mm. mm. mm. mm. mm. Total length 3,810 4,877 [b]4,828 4,597 4,572 [f]4,315 4,605 3,870 3,700 3,450 3,708 **Error unbreakable string:[b]12′6″ 16′ **Error unbreakable string:16′2″ **Error unbreakable string:15′1″ **Error unbreakable string:15′± **Error unbreakable string:=13′9″ **Error unbreakable string:15′1ࡩ″ **Error unbreakable string:12′8″ **Error unbreakable string:12′2″ **Error unbreakable string:11′4″ **Error unbreakable string:12′2″ Tip of upper jaw 470 ... ... [c]572 559 602 475 530 500 440 ... to blowhole Tip of upper jaw ... ... ... ... ... ... ... ... 520 ... ... to eye Tip of lower jaw [d]889 ... ... ... ... 1,098 1,000 970 930 910 ... to pectoral fin Back of dorsal [1,156] ... [e]1,803 ... ... [1,190] 1,590 1,280 [1,130] 1,150 ... to back of flukes Length of base 356 ... 349 324 ... 366 400 340 330 ... ... of dorsal fin Length of eye 25 ... ... ... ... 46 40 37 ... ... ... Length of mouth 248 457 432 ... 343 373 ... ... ... ... ... (upper jaw) Length of mouth ... ... 445 349 356 392 ... 320 320 ... 343 (lower jaw) Length of throat [f]173 ... 298 ... 254 248 ... ... 300 ... ... furrows Distance between 131 ... 241 229 178 157 ... ... 217 ... 254± throat furrows posteriorly Height of dorsal 152 ... 191 203 ... 209 215 170 160 130 ... fin Breadth of flukes 889 ... 1,118 ... ... 994 1,130 1,000 820 680 ... Flukes to anus ... ... ... ... ... ... 1,290 1,090 [950] 1,000 940 Length of [g]279 ... [h]546 ... ... [i]392 515 440 380 ... ... pectoral fin[k] Greatest breadth 95 ... ... ... ... 131 170 120 115 ... ... of pectoral fin

[a] Type-specimen.
[b] Straight.
[c] To center of blowhole.
[d] From tip of upper jaw (curvilinear).
[e] Curvilinear.
[f] Left. The right=192^mm.
[g] Along center. Along anterior border = 292^mm±.
[h] Along anterior border.
[i] Straight; point of measurement not given.
[j] Along side.
[k] From anterior base, unless otherwise indicated.

Since the foregoing account of _europæus_ was written, a description of the type-skull, with two excellent photographic figures, has been published by L. Brasil,[29] of the Caën Museum. A comparison of the figures with those of the Atlantic City and Long Branch skulls on Pls. 2 and 8 of the present article, confirms the identification of the latter specimens with _M. europæus_. Besides a brief description of the type-skull M. Brasil’s paper contains measurements and two text figures of the right mandibular tooth, natural size.

MESOPLODON STEJNEGERI True.

_Mesoplodon stejnegeri_ True, Proc. U. S. Nat. Mus., vol. 8, p. 584.
Oct. 19, 1885.

This species was originally described from a single cranium of a young individual, which was collected by Dr. L. Stejneger on Bering Island, Commander Group, Bering Sea, in 1883. With but a single skull, the characters of the species could not be very satisfactorily defined, and some European cetologists have been inclined to doubt its validity.[30] In 1904, however, another skull was obtained by the National Museum, which made it certain that the species was entirely distinct from _M. bidens_ or other known forms of the genus. Early in the year mentioned Dr. D. S. Jordan, president of Stanford University, called my attention to a small whale, which stranded on the coast of Oregon, 1½ miles south of the United States life-saving station on South Beach, Yaquina Bay, near Newport, in February, and proved later to represent the present species. Doctor Jordan’s information was obtained from Mr. J. G. Crawford, of Albany, Oregon, who wrote him in part as follows, under date of March 7, 1904:

Herewith I enclose a stereograph of a head of a member of the whale
family, which I made at Yaquina Bay, Oregon. The animal was 17 feet
long, with fluked tail, soft, smooth skin, blowhole on top of head, and
two tusks in the mandible, but no [other] teeth in the mouth. The tusks
are thin and apparently hollow. Length of head, 32 inches; width, 14
inches; height, 11 inches; blowhole, 5 inches. Eyes low on head. Width
of mandible [jaw] at end: Upper, 1½ inches; lower, 1¾ inches. Width
between tusks, 3 inches. The blubber was about 2 inches thick on the
head. It went ashore about the 15th of February, 1½ miles south of the
life-saving station on South Beach, 2½ miles south of Newport, Oregon.
The head had been severed before I arrived.

A clipping from the _Oregonian_ newspaper contains the following:

Albany, Oregon, March 2 [1904]. A peculiar specimen of the whale
variety has been reported on the Oregon coast, near Newport. J. G.
Crawford, of Albany, has just returned from a trip to Newport, where he
made a picture of the head of the strange animal. The body was washed
upon the beach during the recent storm which swept the coast. It is
about 15 feet long. * * * Residents of the vicinity say they have never
seen anything like it on the Oregon coast. * * * On either side of the
mouth are two villainous-looking tusks several inches in length. They
are at the back of the mouth, and extend up to a level with the top of
the upper jaw. They are very wide and flat, squared on top. The mouth
has no other teeth. * * *

The head is equipped with a blowhole, like that of a whale. The eyes
are very low, almost underneath the lower jaws.

The body is in a good state of preservation, the flesh having been torn
but little by the birds.

On receipt of the foregoing information, letters were immediately addressed to Mr. Crawford and also to the keeper of the life-saving station at South Beach, Capt. Otto Wellander, asking that, if possible, the entire skeleton be preserved. Captain Wellander replied that the whale had not been dead long when washed ashore; that he had tried to find the body, but that the high tides had either carried it away or buried it under driftwood.

The skull when cleaned passed into the possession of Mr. J. G. Crawford, who sent to the Museum some excellent photographs of it, and also of the head before the flesh had been removed. Later he sent the skull itself to the Museum for my examination, and finally very generously presented it to the Museum in exchange.

The skull is that of an adult individual, in nearly perfect condition, with the mandible and teeth. The parts missing are the left malar, the left tympanic bone, the distal ends of the pterygoids and the proximal ends of the premaxillæ. (Pl. 3, fig. 2.)

SKULL.

The Oregon skull exhibits all the characters included in the original diagnosis of the species,[31] but two of these, namely, the lack of a groove in front of the premaxillary foramen, and the vertical position of the premaxillæ distally, I do not at present consider of any importance, as they are shared by _M. bidens_. The species, as represented by the Oregon skull, however, presents other characters which clearly differentiate it from any other species of the genius. As it is without a basirostral groove, it allies itself in that respect to _M. bidens_, _europæus_, and _hectori_. Unlike those species, it has the premaxillary foramen behind the maxillary foramen, and in this respect resembles _densirostris_ and _grayi_. Perhaps the most salient characters in which _stejnegeri_ differs from _bidens_ and all other known species are the erect position and flat surface of the supraoccipital and the very prominent backward extension of the frontal plate of the maxilla. This backward extension is so great that when the beak is horizontal a vertical line through the posterior margin of the maxilla passes considerably behind the temporal fossa. The only species which approaches _stejnegeri_ in this respect is _hectori_, but in the latter the supraoccipital instead of being flat above the condyles is very strongly convex.

Another very marked character of _stejnegeri_ is that the extension of the lateral free margin of the orbital plate of the frontal, anterior to the orbit, is equal to the length of the orbit itself. In _bidens_ and all other known species this extension is only from one-third to one-half the length of the orbit. Numerous other distinguishing characters will be mentioned in the course of the following description of _stejnegeri_, which is drawn from the adult Oregon skull, but modified when necessary by reference to the type skull from Bering Island. Comparisons are made chiefly with _M. bidens_, which is on the whole the best known species.

In the Oregon skull of _stejnegeri_, the breadth between the post-orbital processes does not exceed the length from the occipital condyles to the maxillary notches. The skull is, therefore, narrower in proportion to its length than in any other species of the genus except _hectori_, as represented by the skull figured by Flower. This skull was, however, that of a young individual. It is probable that in adults of this species the skull is broader than in _stejnegeri_.

In the latter species, again, the length of the brain-case, between the occipital condyles and the maxillary notches, is just equal to the distance from the latter point to the distal end of the maxillæ, and the rostrum, including the premaxillæ, is much shorter than in other species of _Mesoplodon_, except _hectori_, as represented by the young skull above mentioned.

The foramen magnum is very small, being less in width than the condyle on either side of it. In this respect it differs widely from _bidens_ and other species (as far as can be ascertained from the figures available), except _europæus_, in which the relative size is about the same.

The supraoccipital rises vertically above each condyle to the very top of the skull, being neither convex nor strongly bent forward as in other species, and especially _bidens_. In the median line, however, while the occipital bone is flat immediately above the foramen magnum, it is deeply concave higher up and without a median ridge. The outline of the occipital crest, viewed from behind, is semicircular. In all the foregoing characters the occipital region differs widely from that of _bidens_ and other species. The only close resemblance is found in the old skull of _europæus_ from Long Branch, New Jersey, and even here the sides of the occipital above are far less prominent, their outline is much more convex, the occipital crest is angular, and the median depression is less pronounced.

_Dorsal aspect_ (Pl. 3, figs. 1, 2).—The most noticeable feature of the upper surface of the skull is the large backward extension of the frontal plates of the maxillæ, the free margins of which converge strongly. The outline of the anteorbital region is rounded. The anteorbital notch is a shallow emargination. Anterior to this is a second still shallower emargination, the “pseudo-notch.” The margin between the two is much thickened, but does not form a distinct projection or tubercle, as in _bidens_ and other species. The superior orifices of the nares are unsymmetrical as regards position, the left being somewhat in advance of the right. The maxillæ are concave around the maxillary foramen, and external to this foramen is an elongated ridge about as in _europæus_. The rostral portion of the maxillæ is broad at the base but tapers more rapidly than in _bidens_. The margin is thick. At the middle of the beak the outline of the maxillæ at a lower level is visible from above, which is not the case in _bidens_ or _europæus_. The rostral portion of the premaxillæ is oblique proximally and vertical distally. Unlike _bidens_, these edges are sharp throughout. The mesethmoid ends opposite the maxillary foramina. Anterior to it is seen the concave upper surface of the vomer, which, however, becomes flat distally. At about the middle of the beak the anterior end is clasped by the posterior forked end of a “mesirostral” ossification, which has a convex surface. This ossification begins proximally below the edges of the premaxillæ, but its surface rises gradually anteriorly, and at the end of the beak it is much above the premaxillæ. The end of the beak consists of the consolidated mass of the premaxillæ and mesirostral ossification, the whole being convex above and below, but flat on the sides. The ossification has a deep median groove, which reaches to within 95 mm. of the tip of the beak.

It will be seen that the conformation of the upper surface of the beak is quite different from that of _bidens_ or any other species.

The maxillary foramina are large and directed forward, and have a distinct broad channel in front of them. In the Oregon skull the right foramen is single, but the left divided into two. The premaxillary foramina are a little behind the maxillary foramina. The distance between the maxillary foramina is less than that from the median line to the anteorbital notch. In _bidens_ it is much greater.

_Lateral aspect_ (Pl. 9, figs. 1, 2).—A most noteworthy feature of the skull when viewed from the side is the great length between the orbit and the maxillary notch, which far exceeds that found in _bidens_ and other species, being equal to the length of the orbit itself. The latter is about as long as the temporal fossa, which is somewhat flattened above, as in _europæus_. The outline of the supraoccipital is straight and nearly vertical. The zygomatic is more massive even than _europæus_ and is especially thick below. The inferior outline of the beak is convex proximally as in _europæus_ and _layardi_. There is no basirostral groove, the edges of the maxillæ being very thick in front of the maxillary notch. Over the orbit the maxillæ are thick and beveled, but not raised as in _bowdoini_.

_Ventral aspect_ (Pl. 6, figs. 1, 2).—The beak is convex in the proximal half, much as in _europæus_, but farther forward is concave, except in the median line, where there is a narrow ridge formed proximally by the vomer, which in the type skull appears as a narrow lozenge 60 mm. long. In the adult Oregon skull it is anchylosed with the premaxillæ. The maxillæ extend to within 107 mm. of the end of the beak. The under surface of the beak is much more like that of _europæus_ than of _bidens_.

A narrow strip of the palatines extends around the base of the pterygoids in front, but the two strips do not meet in the median line. In the type-skull they do not extend inside the pterygoids. The expanded anterior end of the malar is very long and also forms the bottom of the maxillary notch, which is the case in _europæus_ but not in _bidens_. The inferior borders of the pterygoids are convex anteriorly, as in _europæus_, and are continued laterally, so that the sinus is deep as in that species. The lachrymal is very long, the free margin having a length of 55 mm. The posterior margin of the zygomatic process is concave, rather than convex as in _bidens_.

The tympanic bulla does not differ materially from that of _bidens_ in size or shape, as far as can be judged from the figures given in Van Beneden and Gervais’ Osteography (plate 26, figs. 4, 4_a_). The periotic is similar in size to the same bone in _bidens_, but the posterior end is more narrowly pointed and the anterior end is much lower, relatively. In _europæus_, as far as can be determined from the material at hand, the form and size of the earbone is similar to that of _stejnegeri_, but in the latter the anterior margin of the tympanic bulla is more nearly transverse and the posterior inferior groove is curved. (Pl. 35, fig. 2.)

In the Annisquam skull, supposed to represent _densirostris_, although from a young individual, the earbone is very much larger, especially the periotic, which is also quite differently shaped.

MANDIBLE.

The mandible of _stejnegeri_ is much broken in the region of the angle on both sides, but otherwise complete. As compared with a mandible of an adult _bidens_, the most conspicuous differences are the shortness of the symphysis, the sharp upward bend of the inferior margin anteriorly, and the large size of the alveolus. The symphysis in the adult Oregon specimen of _stejnegeri_ is 140 mm. long, or scarcely more than in the young specimen of _europæus_ from New Jersey, and exactly the same as in the adult type-specimen of the latter species, as figured by Van Beneden and Gervais. The alveolus lies entirely behind the symphysis, its anterior end being 160 mm. from the anterior end of the jaw. It is 113 mm. long and 18 mm. wide. The mandible is 62 mm. high at its middle point. The coronoid process is more anteriorly situated than in _bidens_ and the portion of the posterior margin of the ramus which remains indicates that the angle was strongly directed backward. (Pl. 11, fig. 4; pl. 12, fig. 1.)

TEETH.

The teeth are remarkable for their size and form. They are somewhat more than twice as broad as teeth of adult males of _bidens_, as shown by the figures of Lankester[32] and Grieg,[33] and also a little longer. They are, in fact, probably broader than, or at least as broad as, the teeth of any other species of _Mesoplodon_, not excepting _layardi_. Sir William Turner remarks regarding a specimen of _layardi_ examined by him that “the breadth of the tooth, where it emerged from the alveolus, was 3½ inches.”[34] He does not state, however, whether the measurement was taken along the top of the alveolus, at an angle with the transverse axis of the tooth, or along the transverse axis itself. At all events, the teeth figured by Owen and others are much less than 3½ inches broad. The teeth of adult _europæus_ are only 2 inches broad, and of _bidens_, as already stated, 1½ inches broad.

In _stejnegeri_ (Pl. 12, figs. 1-3) the portion of the tooth above the alveolus is inclined slightly inward and backward, but the pointed tip curves outward so as to be vertical. When extracted from the alveolus, the whole tooth is found to be concave internally and convex externally. The posterior margin is convex and the anterior sinuous, a slight convexity occurring on the portion which projects above the alveolus. In this place the outer coating of cement is broken through, showing the underlying dentine or osteo-dentine, which is somewhat corroded or absorbed. This is particularly noticeable on the left tooth.

The upper margin of the tooth is transverse, or nearly at right angles with the anterior and posterior margins. The posterior angle is rounded and the anterior raised into an acute point by the projection of the dentine as a distinct, sharp cusp. The inferior end of the tooth is cut off obliquely and the margin is broken by numerous prominent rugosities. The surface of all that part of the tooth which is contained in the alveolus and covered by the gum above it is rugose, while the part above the gum is quite smooth and highly polished.

The right tooth has the following dimensions (in straight lines): Length of anterior border, 150 mm.; length of posterior border, 107; length of superior border, 54; length of inferior border, 86; average length of exposed dentine tip, 10; greatest breadth of tooth, antero-posteriorly, 81; greatest breadth of tooth, transversely, 15; distance from center of base of exposed portion, when in position in the alveolus, to tip of dentine projection, 82; distance from center of base of portion above the gum to tip of dentine projection, 70; distance from center of base of portion above the gum to center of inferior margin, 76.

The dimensions of the skulls are as follows, those of the type-specimen having been revised and corrected:

_Dimensions of two skulls of M. stejnegeri._

Column headings:
A: 143132 U.S.N.M. Yaquina Bay, Oregon, adult.
B: 21112 U.S.N.M. Bering Id. Type (1715), young.

Measurements. A B
Total length 715 [a]633
Length of rostrum 413 [a]325
Distance from occipital condyles to distal end of 612 567
maxillæ
Breadth between centers of orbits 309 279
Breadth between zygomatic processes 310 278
Breadth between temporal fossæ 228 212
Breadth between postorbital processes of frontals 323 ...
Breadth of rostrum at base (between maxillary 172 [b]158
notches)
Breadth of rostrum at middle 40 44
Depth of rostrum at middle 52 42+
Greatest breadth of anterior nares 56 54
Greatest breadth of premaxillæ proximally 130 118
Greatest breadth of premaxillæ in front of nares 108 109
Length of temporal fossa 92 86
Depth of temporal fossa 63 46
Antero-posterior length of orbit 96 82
Breadth of foramen magnum 38 39
Length of tympanic bulla 48 ...
Breadth of tympanic bulla 32 ...
Length of mandible 610 ...
Length of symphysis 138 ...
Distance from anterior end of mandible to alveolus 166 ...

[a] Tip of rostrum lacking.
[b] The skull is much worn around the left notch and the measurement is
only approximate.

EXTERNAL FORM.

The photograph of the head (Pl. 40, fig. 4) shows that the end of the beak was quite blunt, and the lower jaw quite a little longer than the upper. The superior margin of the lower jaw, which is concave in front of the tooth, is strongly convex and elevated at the side of it and behind it. The inferior margin of the upper jaw is straight anteriorly, but farther back appears to be pressed upward by the tooth. An examination of the skull shows that the mandible can be lowered so that the teeth are below the upper jaw, but when so lowered the space between the teeth and the upper jaw on each side is barely a quarter of an inch (6 mm.). With the integuments in place, it is doubtful whether the mouth could be opened any wider than is shown in the photograph. The convexity of the head, shape of the blowhole, position of the eye, etc., do not appear to differ materially from the same characters in adults of _M. bidens_.

Genus ZIPHIUS Cuvier.

ZIPHIUS CAVIROSTRIS Cuvier.

_Ziphius cavirostris_ Cuvier, Oss. foss., 2d ed., vol. 5, 1823, p. 353.
_Hyperoödon gervaisii_ Duvernoy, Ann. Sci. Nat., ser. 3, Zoöl., vol.
5, 1851, p. 49.
_Ziphius gervaisii_ Fischer, Nouv. Arch. Mus. Paris, vol. 3, 1867, p.
55.
_Hyperoödon semi-junctus_ Cope, Proc. Acad. Nat. Sci. Phila., 1865,
p. 15.
_Ziphius semijunctus_ True, Proc. U. S. Nat. Mus., vol. 8, 1886, p.
586.
_Ziphius grebnitzkii_ Stejneger, Proc. U. S. Nat. Mus., vol. 6, 1883,
p. 77.

It has not seemed to me necessary in the present connection to attempt to cite all the multitudinous names which have been given to this species, especially as those zoologists most competent to judge, including Van Beneden, Flower, and Turner, after detailed consideration, have concluded that but one species of _Ziphius_, or at most two species, exist at present.[35]

Nearly all the skulls in European museums are assigned by the zoologists mentioned to _Z. cavirostris_ proper, but some doubt has been entertained regarding two or three European skulls, and one specimen from Argentina, described by Burmeister. These last-mentioned specimens have been thought to possibly represent a second species, _Z. gervaisii_. The principal characters of the latter are the narrow, flat premaxillæ, the lack of a prominent mesirostral ossification, and small teeth. From the large series of skulls in the National Museum, I am able to dispose of the doubt concerning _Z. gervaisii_. I find that wherever the characters above mentioned occur the sex (when known) is female. There is every reason, therefore, to believe that _Z. gervaisii_ is the female of _Z. cavirostris_.[36] I will return to this point again later.

In 1865 Cope described a species from Charleston, South Carolina, under the name of _Hyperoödon semijunctus_. In 1886 I referred it to the genus _Ziphius_, but was in doubt as to its specific identity. I thought that it might represent _Z. gervaisii_, which is interesting in the present connection because the type-specimen was a female.

In 1883 Dr. L. Stejneger described a species which he had discovered on Bering Island, Bering Sea, under the name of _Z. grebnitzkii_. Through the instrumentality of Doctor Stejneger and Governor Grebnitzki, the National Museum later received a large series of skulls from the same locality. The question of whether this species is identical with _Z. cavirostris_, or distinct, has caused me much study, and forms the principal subject of this chapter.

The National Museum has at present the following material, which may be considered as certainly representing _Z. cavirostris_:

1. A complete skeleton and cast of an adult female, 19 feet 4 inches long, obtained at Barnegat City, New Jersey, October 3, 1883. Cat. No. 20971.

2. A complete skeleton and photographs of an adult male, 20 feet 1 inch long, obtained at Newport, Rhode Island, in 1901, through Dr. E. A. Mearns, Mr. L. di Z. Mearns, and Capt. Gus Soderman. Cat. No. 49599.

3. The collection contains also the skeleton of the young female individual obtained at Charleston, South Carolina, prior to 1865, which constitutes the type of _Hyperoödon semijunctus_ Cope. It was originally in the Charleston College Museum, but later was received by the National Museum in exchange. This individual was between 12 and 13 feet long. Cat. No. 21975.

In addition, the national collections contain the following material, known to, or supposed to, represent the species _Z. grebnitzkii_:

4. Cat. No. 20993. Skull of a male (?).[37] Collected by Dr. L. Stejneger in Bering Island, 1882. Orig. No. 1521. Type of _Ziphius grebnitzkii_.

5. Cat. No. 21245. Skull. Orig. No. 1758.

6. Cat. No. 21246. Skull. Orig. No. 2531.

7. Cat. No. 21247. Skull. Orig. No. 1849.

8. Cat. No. 21248. Skull of a male (?).

9. Cat. No. 83991. Skull.

The five skulls preceding were also collected by Doctor Stejneger in Bering Island in 1882 and 1883.

10. Cat. No. 22069. Skull of a female (?).[37]

11. Cat. No. 22874. Skull.

12. Cat. No. 22875. Bones of an immature individual.

These three specimens were collected and presented by N. Grebnitzki.

13. Cat. No. 142579. A series of photographs of an individual captured in Kiska Harbor, Alaska, September, 1904. Presented by Dr. J. Hobart Egbert.

14. Cat. No. 84906. Photograph of the skeleton of an individual washed ashore at St. Simon Island, Georgia, in 1893, and belonging to Mr. W. Arnold.

In the genus _Ziphius_, as in other ziphioid genera, a study of the characters of the skull appears to afford the best basis for discrimination of species. We have first to consider whether the North American species is the same as the European and New Zealand species, and afterwards whether the North Pacific species is identical with or distinct from these.

The published measurements of specimens from the coasts of Europe and New Zealand, currently believed to represent the single species _Z. cavirostris_, are rather meager, and, furthermore, prove, on examination, to present so little uniformity that they are of limited use for comparison with measurements of skulls from the Atlantic coast of the United States. About all that can be said is that the latter skulls are of about the same size as the former and that the proportions do not present any striking differences. For detailed measurements of the American skulls, see page 53.

On account of the uncertainty as regards the measurements, I have had recourse to the published descriptions and figures, especially those of Van Beneden, Sir William Turner, and Doctor Haast. So far as I can perceive, there is nothing in these descriptions that is not applicable to the skulls Nos. 49599 and 20971, from Newport, Rhode Island, and Barnegat City, New Jersey, respectively, in the National Museum, and I can find no reason for regarding the latter other than as representatives of _Z. cavirostris_.

HISTORY OF THE NEWPORT, RHODE ISLAND, SPECIMEN.

Of the Newport specimen, No. 49599, the Museum has the complete skeleton, together with external measurements and a photograph. From data at hand it appears that the animal was originally obtained in Narragansett Bay about October 30, 1901, and afterwards towed to Fort Adams, near Newport. A few days later it was sent adrift again and stranded in the harbor of Dutch Island, near Canonicut Island, which is opposite Newport. While at Fort Adams its existence was made known to the Museum by Dr. E. A. Mearns, U. S. Army, and his son, Louis Mearns; and a preparator was sent to obtain the skeleton. With the aid of Captain Soderman, of the government tug _Monroe_, he found it at Dutch Island, and reported that it was a male, 20 feet 1 inch in length, measured along the curves of the back (18 feet 6 inches in a straight line). The epidermis was nearly all lacking, but the back appeared to have been black. The length in a straight line, as reported by Mr. Louis Mearns, was 19 feet. The complete measurements taken by the preparator, Mr. J. W. Scollick, are as follows:

_External dimensions of Ziphius cavirostris, male, Cat. No. 49599,
U.S.N.M., Newport, Rhode Island._

Ft. in.
Total length, along curve of back 20 1
Total length, in straight line 18 6
Tip of snout to posterior margin of dorsal fin 13 10
Tip of snout to axilla 5 2
Tip of snout to eye 2 5½
Tip of snout to anterior margin of blowhole 2 4
Length of mouth 1 1
Breadth of blowhole 0 5½
Length of pectoral fin, from head of humerus to tip, 2 2
straight
Vertical height of dorsal fin 0 10
Breadth of flukes, from tip to tip 5 3
Greatest girth (estimated) 10 0

The breadth of the pectoral fin, as shown by the skeleton, was 5¾ inches.

The photograph, which is reproduced in Pl. 41, fig. 4, gives a good idea of the general form of the animal.

HISTORY OF THE BARNEGAT CITY, NEW JERSEY, SPECIMEN.

Of the Barnegat City specimen, No. 20971, the Museum has the complete skeleton, together with a cast of one-half of the entire animal, and another of the head, and some measurements, all of which were obtained by Mr. William Palmer and myself October 3, 1883. The Museum received notice of the stranding of this specimen from Capt. J. H. Ridgway, of the United States life-saving station at Barnegat City. It was an adult female, 19 feet 4 inches long in a straight line. The complete measurements, taken in straight lines with a rod and cord, are as follows:

_External dimensions of Ziphius cavirostris, female, Cat. No. 20971,
U.S.N.M., Barnegat City, New Jersey._
(Measured in straight lines with rope and bar.)

Ft. in.
Total length 19 4
Tip of snout to eyes 2 1
Tip of snout to blowhole 2 0
Tip of snout to anterior base of pectoral fin 3 10½
Tip of snout to anterior base of dorsal fin 12 0
Tip of snout to anterior angle of vent 12 3½
Tip of snout to corner of mouth 11½
Length of anterior margin of pectoral fin 2 1½
Length along center of pectoral fin 1 7
Greatest breadth across pectoral fin 6¾
Length of anterior margin of dorsal fin 1 6
Length of base of dorsal fin 1 0
Vertical height of dorsal fin 1 0
Breadth of flukes from tip to tip 5 5
Antero-posterior length of flukes 1 7
Length of eye 2
Breadth of eye 1
Girth around eyes 3 1½
Girth at anterior margin of dorsal fin 7 0½
Girth at root of pectoral fins 6 0½
Breadth of lower jaw at middle of length 4½
Breadth of upper jaw at middle of length 5
Breadth of blowhole 5
Distance from posterior angle of eye to ear 4½

I neglected to make a full description of the color, but noted that it was stone gray, lighter above and darker below; snout nearly white. The cast, which was painted from a sketch made at Barnegat City and from pieces of skin brought to Washington, bears out this note in general, but with modifications. The color of the body as a whole is gray tinged with dull yellowish. The gray is darker on the back than on the belly, but on the latter is a large area of dark brown, reaching from near the pectoral fins to and beyond the anus, and halfway up on the sides. On this dark area are several large oval whitish blotches, some two inches in diameter. Both upper and lower jaws nearly to the angle of the mouth are cream white. On the sides and belly the gray color is speckled with black spots of about the size of a grain of wheat. The pectoral fins are dark gray above and below; the flukes were similarly colored.

A comparison of the dimensions of the two specimens above described with those of European and New Zealand specimens is afforded by the following table (the measurements being reduced to percentages of the total length):

_External dimensions of Ziphius cavirostris. (Reduced to percentages of
the total length.)_

Column Headings:
A: Newport, Rhode Island 49599 U.S.N.M., male, 1901.
B: Barnegat City, New Jersey, 20971 U.S.N.M., female, 1883.
C: New Brighton, New Zealand, female.
D: Punta, Corsica, 1842.
E: Buenos Ayres, Argentina, male, 1865.

Measurements. A[a] A[b] B[b] C D E
Ft. in. Ft. in. Ft. in. Ft. in. Ft. in. Ft. in.
Total length 20 1 18 6 19 4 19 6 19 0 12 11½
Per cent. Per cent. Per cent. Per cent. Per cent. Per cent.
Tip of snout to 69.0 74.8 67.2 [67.1] [78.5] [70.8]
posterior margin
of dorsal
Tip of snout to 25.3 28.0 [c]20.0 [d]24.4 ... [c][25.0]
axilla
Tip of snout to eye [k]12.2 13.3 10.8 12.8 ... 10.9
Tip of snout to 11.2 12.6 10.4 ... ... 11.4
anterior end
blowhole
Length of mouth 5.4 5.9 [e] 5.0 6.4 ... [ f] 5.3
Breadth of blowhole 2.3 2.5 2.2 2.6 ... 1.2
Length of pectoral 10.8 11.7 ... [g]12.8 ... ...
from head of
humerus
Length of pectoral [h]7.5 8.1 [hi]8.1 ... [g] 8.3 8.6
from axilla
Greatest breadth of [j]2.4 [j]2.6 2.9 3.0 2.9 3.0
pectoral fin
Vertical height of 4.1 4.5 5.2 3.4 3.5 4.3
dorsal fin
Breadth of flukes, 26.1 28.4 28.0 31.2 ... 27.3
tip to tip fin

[a] Curvilinear.
[b] Straight.
[c] To anterior base.
[d] Lower jaw to “beginning of pectoral.”
[e] From tip of upper jaw.
[f] From tip of lower jaw.
[g] Points of measurements not specified.
[h] From the bones; from outer anterior margin of proximal expansion of
ulna.
[i] Along center.
[j] From the bones. The external measurement originally taken by
Scollick is entirely too large.
[k] The skull gives this measurement as 10.4 per cent. The original
measurement by Scollick is entirely too large and can not be
correct. The same is probably true regarding length to
blowhole, but I can not prove it.

The close correspondence in proportions shown in this table favors the idea of specific identity, and taken with the similarity in size, and characters of the skull, warrants, I think, the assumption that the specimens from the Atlantic coast of the United States belong to _Z. cavirostris_.

COLORATION.

It should be remarked, however, that the Barnegat City specimen does not agree in color with any of the European or New Zealand specimens. On the other hand, the latter show a most extraordinary diversity in color, some being black, with the head and back as far as the dorsal fin white; others all black above, white below, and the head black and brown. The color of the young specimen from Buenos Ayres, Argentina, is described by Burmeister as follows:

All the body of the animal is of a light gray color, a little
yellowish, resembling the color of light ash, but much darker on the
back and much lighter on the belly. The fins are much darker than the
back—almost black—and the large fin of the tail has a very pure white
area of irregular shape on the underside.

If the indications from the skull and proportions are trustworthy _Z. cavirostris_ must be a species in which the color is very variable, differing perhaps in the two sexes, or with differences in age. This is, however, by no means certain at present, and whether the diversities of color reported in different specimens are merely individual variations, or are due to post-mortem changes, remains to be discovered. It will be noticed that the color of the Argentine specimen is nearest to that of the Barnegat City specimen.

TYPE OF ZIPHIUS SEMIJUNCTUS (COPE).

The type-specimen of _Ziphius semijunctus_ (Cope), as already mentioned, is a young female.[38] The most noticeable characters which it presents are that the premaxillæ are flat proximally, and that the teeth are small, sharp-pointed and open at the roots. The form of the teeth is undoubtedly due to immaturity, but as the shape of the premaxillæ is similar to that found in the nominal species _gervaisii_, it might be thought necessary to refer _semijunctus_ to the latter species. As will be shown later, however, this form of the premaxillæ appears to be characteristic of the adult female of _cavirostris_, and of immature individuals of either sex, the young, as in many kinds of animals, resembling the adult female rather than the male.

I have been able to find but one character in the skull of _semijunctus_ which might be regarded as specific. This is that the lachrymal bone is thick distally, and cut off square at the end. In other specimens of _Ziphius_ examined it is thin and flat, and rounded or pointed at the end. As there is much individual variation in the form of the lachrymal, this peculiarity alone is, in my opinion, an insufficient indication of the validity of the species.

COMPARISON OF SKELETONS.

A comparison of the skeletons of the three individuals from the Atlantic coast of the United States reveals a number of differences of more or less importance. Were it not for the lack of reliable differences in the skulls, it might be considered that these variations in other parts of the skeletons indicated specific difference. I am disposed, however, since the Barnegat and Newport specimens are of opposite sexes, to regard them partly as sexual and partly as individual. In the case of the Charleston specimen (_semijunctus_), the skeleton, besides being immature, has been very much damaged by careless handling, and nearly all the bones are somewhat abraded. It is, therefore, only available to a limited extent for purposes of comparison. As no description of a _Ziphius_ skeleton from the coast of the United States has, so far as I am aware, been published hitherto, and as descriptions of skeletons of Old World specimens are few and rather brief, I shall give below a detailed comparative description of the American specimens. For the sake of brevity, I shall refer to each specimen merely by the locality.

VERTEBRAL COLUMN AS A WHOLE.

The vertebral formula in the three North American specimens and in four Old World specimens and Burmeister’s Argentine specimen is as follows:

_Vertebral formula of Ziphius cavirostris._

Locality and sex. C. Th. L. Ca. Total.
Newport, Rhode Island, male 7 9 10 20 46
Barnegat City, New Jersey, female 7 9 11 18(+1?) 46(?)
Charleston, South Carolina, female 7 10 10 16(+3?) 46(?)
Holma, Sweden (Malm) 7 10 10 18(+1) 46
Pisa Museum (Van Beneden) 7 9 11 16+ 43+
Warrington, New Zealand (Scott and 7 10 9 20 46
Parker)
Lyttleton Harbor, New Zealand 7 9 11 19 46
(Haast)
Buenos Ayres, Argentina 7 10 10 22 49
(Burmeister), male

In the figures of the Argentine specimen the last ten caudals are practically without characters, and it is perhaps allowable to question whether the terminal two or three were not added to make an even taper to the end of the column. If such be not the case, this specimen had more vertebræ than any other.

CHARACTERS OF THE VERTEBRÆ.

_Newport_ (male).—The seventh cervical vertebra presents a conical metapophysis, which on the first thoracic vertebra forms of a rather thick, long, declining process ending in a facet for the tubercle of the first rib. This metapophysis maintains nearly the same form as far as the sixth thoracic vertebra, but on the third thoracic a mammiliform process makes its appearance on the anterior margin near the tip, and becomes more prominent on each succeeding vertebra. On the seventh thoracic it becomes larger, thin, and upright, and widely separated from the articular facet for the tubercle of the rib. On the centrum of this vertebra lower down is a second much larger rugose articular facet. On the eighth thoracic vertebra the upper articular process disappears altogether and is replaced by a transverse process on a lower level, with a facet at the free end for the rib. On the ninth thoracic the transverse processes are larger and nearly straight. They are longer on the first lumbar and incline a little forward. Those of the succeeding vertebræ are similar, but decrease gradually in length, while somewhat increasing in breadth. They are last traceable on the ninth caudal. On the eighth caudal they are perforated by a foramen.

All the vertebræ from the first cervical backward have neural spines as far as and including the eleventh caudal. The spine on the first thoracic is rather short, narrow and pointed. These spines increase in height in succeeding vertebræ as far as the sixth lumbar; at the same time the breadth increases antero-posteriorly and the tip becomes expanded. The spines are nearly equally high on all the succeeding lumbars, but begin to decrease on the caudals and disappear altogether on the eleventh caudal.