Chapter VII: Fossil Sponges, Corals and Graptolites

_SPONGES._

=Characteristics of Sponges.--=

The Sponges are sometimes placed by themselves as a separate phylum, the Porifera. With the exception of a few freshwater genera, they are of marine habit and to be found at all depths between low tide (littoral) and deep water (abyssal). Sponges are either fixed or lie loosely on the sea-floor. They possess no organs of locomotion, and have no distinct axis or lateral appendages. They exist by setting up currents in the water whereby the latter is circulated through the system, carrying with it numerous food particles, their tissues being at the same time oxygenated. Their framework, in the siliceous and calcareous sponges, is strengthened by a mineral skeleton, wholly or partially capable of preservation as a fossil.

=Cambrian and Ordovician Sponges.--=

The oldest rocks in Australia containing the remains of Sponges are the Cambrian limestones of South Australia, at Ardrossan and elsewhere. Some of these sponge-remains are referred to the genus _Protospongia_, a member of the Hexactinellid group having 6-rayed skeletal elements. When complete, the _Protospongia_ has a cup- or funnel-shaped body, composed of large and small modified spicules, which form quadrate areas, often seen in isolated or aggregated patches on the weathered surface of the rock. _Protospongia_ also occurs in the Lower Ordovician slates and shales of Lancefield (_P. oblonga_), and Bendigo (_P. reticulata_ and _P. cruciformis_), in Victoria (Fig. 67 A). At St. David's, in South Wales, the genus is found in rocks of Middle Cambrian age. The South Australian limestones in which _Protospongia_ occurs are usually placed in the Lower Cambrian.

A--Protospongia reticulata, T. S. Hall. Low. Ordovician. Bendigo.

B--Receptaculites fergusoni, Chapm. Silurian. Wombat Creek, Vict.

C--R. australis, Salter. (Section of wall, etched, after Eth. & Dun)
Mid. Devonian. Co. Murray, N.S.W.

D--Protopharetra scoulari, Eth. fil. Cambrian. S.A.

]

Another genus of Sponges, _Hyalostelia_, whose affinities are not very clear, occurs in the South Australian Cambrian at Curramulka. This type is represented by the long, slightly bent, rod-like spicules of the root-tuft, and the skeletal spicules with six rays, one of which is much elongated.

_Stephanella maccoyi_ is a Monactinellid sponge, found in the Lower Ordovician (Bendigo Series) of Bendigo, Victoria.

=Silurian Sponges.--=

Numerous Sponges of Silurian age are found in the neighbourhood of Yass, New South Wales, which belong to the Lithistid group, having irregular, knotty and branching spicules. These sponges resemble certain fossil fruits, generally like diminutive melons; their peculiar spicular structure, however, is usually visible on the outside of the fossil, especially in weathered specimens. The commonest genus is _Carpospongia_.

=Receptaculites: Silurian to Carboniferous.--=

In Upper Silurian, Devonian, and Carboniferous times the curious saucer- or funnel-shaped bodies known as _Receptaculites_ must have been fairly abundant in Australia, judging by their frequent occurrence as fossils. They are found as impressions or moulds and casts in some of the mudstones and limestones of Silurian age in Victoria, as at Loyola and Wombat Creek, in west and north-east Gippsland respectively. In the Devonian limestones of New South Wales they occur at Fernbrook, near Mudgee, at the Goodradigbee River, and at Cavan, near Yass; also in beds of the same age in Victoria, at Bindi, and Buchan (Fig. 67, B.C.). _Receptaculites_ also occur in the Star Beds of Upper Devonian or Lower Carboniferous age in Queensland, at Mount Wyatt. It will thus be seen that this genus has an extensive geological range.

=Carbopermian Sponges.--=

A Monactinellid Sponge, provisionally referred to _Lasiocladia_, has been described from the Gympie beds of the Rockhampton District, Queensland. _Lasiocladia_, as well as the Hexactinellid Sponge _Hyalostelia_, occurs in the Carbopermian of New South Wales.

=Cretaceous Sponges.--=

No sponge-remains seem to occur above the Carbopermian in Australia until we reach the Cretaceous rocks. In the Lower Cretaceous series in Queensland a doubtful member of the Hexactinellid group is found, namely, _Purisiphonia clarkei_. In the Upper Cretaceous of the Darling Downs District pyritized Sponges occur which have been referred to the genus _Siphonia_, a member of the Lithistid group, well known in the Cretaceous of Europe.

=Cainozoic Sponges.--=

A white siliceous clay, supposed to be from a "Deep Lead," in the Norseman district in Western Australia, has proved to consist almost entirely of siliceous sponge-spicules, belonging to the Monactinellid, the Tetractinellid, the Lithistid, and the Hexactinellid groups (Fig. 69 A, B). The reference of the deposit to a "deep lead" or alluvial deposit presents a difficulty, since these sponge-spicules represent moderately deep water marine forms. This deposit resembles in some respects the spicule-bearing rock of Oamaru, New Zealand, which is of Miocene age.

A--Latrunculia sp. (after Hinde). Cainozoic. Deep Lead, Norseman, W.A.

B--Geodia sp. (after Hinde). Cainozoic. Deep Lead, Norseman, W.A.

C--Ecionema newberyi. McCoy sp. Cainozoic. Boggy Creek, Gippsland,
Vict.

D--Plectroninia halli, Hinde. Cainozoic (Janjukian). Moorabool, Vict.

E--Tretocalia pezica, Hinde. Cainozoic. Flinders, Vict.

]

A--Cyathophyllum approximans, Chapm. Silurian (Yer.). Gippsland, Vict.

B--Favosites grandipora, Eth. fil. Silurian (Yer.). Lilydale, Vict.

C--Favosites grandipora, vertical section. Ditto.

D--F. grandipora, transverse section. Ditto.

E--Pleurodictyum megastomum, Dun. Lilydale, Vict.

F--Halysites peristephesicus, Eth. fil. Silurian. N.S. Wales.

G--Heliolites interstincta, Wahl sp Vict. (transv. sect). Silurian..

]

In the Cainozoic beds of southern Australia Sponges with calcareous skeletons are not at all uncommon. The majority of these belong to the Lithonine section of the Calcispongiae, in which the spicules are regular, and not fixed together. Living examples of these sponges, closely related to the fossils, have been dredged from the Japanese Sea. The fossils are found mainly in the Janjukian, at Curlewis, in the Moorabool River limestones, and in the polyzoal rock of Flinders, all in Victoria. They belong to the genera _Bactronella_, _Plectroninia_ and _Tretocalia_ (Fig. 68, D and E). Some diminutive forms also occur in the older series, the Balcombian, at Mornington, namely, _Bactronella parvula_. At Boggy Creek, near Sale, in Victoria, a Tetractinellid Sponge, _Ecionema newberyi_, is found in the Janjukian marls; spicules of this form have also been noted from the clays of the Altona Bay coal-shaft (Fig. 68 C).

* * * * *

The _ARCHAEOCYATHINAE_: an ancient class of organisms related both to the Sponges and the Corals.

=Archaeocyathinae in Cambrian Strata.--=

These curious remains have been lately made the subject of detailed research, and it is now concluded that they form a group probably ancestral both to the sponges and the corals. They are calcareous, and generally cup-shaped or conical, often furnished at the pointed base with roots or strands for attachment to the surrounding reef. They have two walls, both the inner and the outer being perforated like sponges. As in the corals, they are divided by transverse septa and these are also perforated. Certain of the genera as _Protopharetra_ (Fig. 67 D), _Coscinocyathus_, and _Archaeocyathina_, are common to the Cambrian of Sardinia and South Australia, whilst other genera of the class are also found in Siberia, China, Canada and the United States. A species of _Protopharetra_ was recently detected in a pebble derived from the Cambrian limestone in the Antarctic, as far south as 85 deg. An _Archaeocyathina_ limestone has also been found in situ from Shackleton's farthest south.

_CORALS_ (Class Anthozoa).

=Rugose Corals.--=

Many of the older types of Corals from the Palaeozoic rocks belong to the Tetracoralla (septa in multiples of four), or Rugosa (i.e., with wrinkled exterior).

=Ordovician Corals.--=

In Great Britain and North America Rugose Corals are found as early as Ordovician times, represented by _Streptelasma_, _Petraia_, etc. In Australia they seem to first make their appearance in the Silurian period.

=Silurian Corals.--=

In rocks of Silurian age in Australia we find genera like _Cyathophyllum_ (with single cups or compound coralla), _Diphyphyllum_, _Tryplasma_ and _Rhizophyllum_, the first-named often being very abundant. The compound corallum of _Cyathophyllum approximans_ presents a very handsome appearance when cut transversely and polished. This coral is found in the Newer Silurian limestone in Victoria; it shows an alliance with _C. mitchelli_ of the Middle Devonian of the Murrumbidgee River, New South Wales (Fig. 69 A).

=Silurian Hexacoralla.--=

It is, however, to the next group, the Hexacoralla, with septa in multiples of six, twelve, and twenty-four, that we turn for the most varied and abundant types of Corals in Silurian times. The genus _Favosites_ (Honey-comb Coral) is extremely abundant in Australian limestones (Fig. 69 B, C), such as those of Lilydale, Walhalla, and Waratah Bay in Victoria, and of Hatton's Corner and other localities near Yass, in New South Wales. _Pleurodictyum_ is also a familiar type in the Australian Silurian, being one of the commonest corals in the Yeringian stage; although, strange to say, in Germany and N. America, it is typical of Devonian strata (Fig. 69 E). _Pleurodictyum_ had a curious habit of growing, barnacle fashion, on the side of the column of the crinoids or sea-lilies which flourished in those times. _Syringopora_, with its funnel-shaped tabulae or floor partitions, is typical of many Australian limestones, as those from Lilydale, Victoria, and the Delegate River, New South Wales. _Halysites_ (Chain Coral), with its neat strings of tubular and tabulated corallites joined together by their edges, is another striking Coral of the Silurian period (Fig. 69 F). This and the earlier mentioned _Syringopora_, is by some authors regarded as belonging to the Alcyonarian Corals (typically with eight tentacles). _Halysites_ is known from the limestones of the Mitta Mitta River, N.E. Gippsland, Victoria; from the Molong and Canobolas districts in New South Wales; from the Gordon River limestone in Tasmania; and from Chillagoe in Queensland. Abroad it is a well known type of Coral in the Wenlockian of Gotland in Scandinavia, and Shropshire in England, as well as in the Niagara Limestone of the United States.

=Silurian Octocoralla.--=

Perhaps the most important of the Octocoralla is _Heliolites_ ("Sunstone"), which is closely allied to the Blue Coral, _Heliopora_, a frequent constituent of our modern coral reefs. The genus _Heliolites_ has a massive, calcareous corallum, bearing two kinds of pores or tubes, large (autopores) containing complete polyps, and small (siphonopores) containing the coenosarc or flesh of the colony. Both kinds of tubes are closely divided by tabulae, whilst the former are septate. _Heliolites_ is of frequent occurrence in the Silurian limestones of New South Wales and Victoria (Fig. 69 G).

=Devonian Corals.--=

The Middle Devonian beds of Australia are chiefly limestones, such as the Buchan limestone, Victoria; the Burdekin Series, Queensland; and the Tamworth limestone of New South Wales. These rocks, as a rule, are very fossiliferous, and the chief constituent fossils are the Rugose and Perforate Corals. _Campophyllum gregorii_ is a common form in the Buchan limestone (Fig. 70 A), as well as some large mushroom-shaped _Favosites_, as _F. gothlandica_ and _F. multitabulata_. Other genera which may be mentioned as common to the Australian Middle Devonian rocks are, _Cyathophyllum_, _Sanidophyllum_ and _Spongophyllum_, _Heliolites_ is also found in limestones of this age in New South Wales and Queensland.

A--Campophyllum gregorii, Eth. fil. Mid. Devonian. Buchan, Vict.

B--Pachypora meridionalis, Nich. & Eth. fil. Mid Devonian. Queens.

C--Aulopora repens, Kn. & W. (after Hinde). Devonian. Kimberley
district, W.A.

D--Zaphrentis culleni, Eth. fil. Carboniferous. New South Wales.

E--Trachypora wilkinsoni, Eth. fil. Carbopermian (Up. Marine Ser.) New
South Wales.

F--Stenopora crinita, Lonsdale. Carbopermian (Up. Mar. Ser.) N.S.W.

]

In the Burdekin Series (Middle Devonian) in Queensland we also find _Cystiphyllum_, _Favosites gothlandica_, and _Pachypora meridionalis_ (Fig. 70 B), whilst in beds of the same age at Rough Range in Western Australia are found _Aulopora repens_ (Fig. 70 C), and another species of _Pachypora_, namely, _P. tumida_.

=Carbopermian Corals.--=

The only true Carboniferous marine fauna occurring in Australia, appears to be that of the Star Beds in Queensland, but so far no corals have been found. The so-called Carboniferous of Western Australia may be regarded as Carbopermian or even of Permian age. The marine Carbopermian beds of New South Wales contain several genera of Corals belonging to the group Rugosa, as _Zaphrentis_ (Fig. 70 D), _Lophophyllum_, and _Campophyllum_. Of the Tabulate corals may be mentioned _Trachypora wilkinsoni_, very typical of the Upper Marine Series (Fig. 70 E) and _Cladochonus_.

In the Gympie beds of the same system in Queensland occur the following rugose corals, _Zaphrentis profunda_ and a species of _Cyathophyllum_.

In the Carbopermian of Western Australia the rugose corals are represented by _Amplexus_, _Cyathophyllum_, and _Plerophyllum_, which occur in rocks on the Gascoyne River.

The imperfectly understood group of the Monticuliporoids, by some authors placed with the Polyzoa (Order Trepostomata), are well represented in Australia by the genus _Stenopora_ (Fig. 70 F). The corallum is a massive colony of long tubes set side by side and turned outwards, the polyp moving upwards in growth and cutting off the lower part of the tube by platforms like those in the tabulate corals. Some of the species of _Stenopora_, like _S. tasmaniensis_, of New South Wales and Tasmania, are found alike in the Lower and Upper Marine Series. _S. australis_ is confined to the Bowen River Coal-field of Queensland. _Stenopora_ often attains a large size, the corallum reaching over a foot in length.

Neither Jurassic or Cretaceous Corals have been found in Australasia, although elsewhere as in Europe and India, the representatives of modern corals are found in some abundance.

=Cainozoic Corals.--=

In Tertiary times the marine areas of southern Australia were the home of many typical solitary Corals of the group of the Hexacoralla. In the Balcombian beds of Mornington, Victoria, for instance, we have genera such as _Flabellum_, _Placotrochus_, _Sphenotrochus_, _Ceratotrochus_, _Conosmilia_, _Trematotrochus_, _Notophyllia_ and _Balanophyllia_ (Fig. 71).

A--Flabellum victoriae, Duncan. Balcombian. Mornington, Vict.

B--Placotrochus deltoideus, Dunc. Balcombian. Muddy Creek, Hamilton,
Vic.

C--Balanophyllia seminuda, Dunc. Balcombian. Muddy Creek, Hamilton,
Vic.

D--Stephanotrochus tatei, Dennant. Janjukian. Torquay, near Geelong,
Vict.

E--Thamnastraea sera, Duncan. Janjukian. Table Cape, Tas.

F--Graphularia senescens. Tate sp. Janjukian. Waurn Ponds, near
Geelong, Vic.

G--Trematotrochus clarkii, Dennant. Kalimnan. Gippsland Lakes, Vic.

]

Corals especially characteristic of the Janjukian Series are _Paracyathus tasmanicus_, _Stephanotrochus tatei_, _Montlivaltia variformis_, _Thamnastraea sera_ and _Dendrophyllia epithecata_. The stony axis of the Sea-pen, _Graphularia senescens_, a member of the Octocoralla, is also typical of this stage, and are called "square-bones" by the quarrymen at Waurn Ponds, near Geelong, where these fossils occur.

The Kalimnan Corals are not so abundantly represented as in the foregoing stages, but certain species of _Flabellum_ and _Trematotrochus_, as _F. curtum_ and _T. clarkii_, are peculiar to those beds. Several of the Janjukian Corals persist into Kalimnan times, some dating as far back as the Balcombian, as _Sphenotrochus emarciatus_. The Sea-pen, _Graphularia senescens_ is again found at this higher horizon, at Beaumaris; it probably represents a varietal form, the axis being smaller and more slender.

Other examples of the Octocoralla are seen in _Mopsea_, two species of which are found in the Janjukian at Cape Otway; the deeper beds of the Mallee; and the Mount Gambier Series.

A species of the Astraeidae (Star-corals) of the reef-forming section, _Plesiastraea st.vincenti_, is found in the Kalimnan of Hallett's Cove, South Australia.

_HYDROZOA._

The few animals of this group met with in fossil faunas are represented by the living _Millepora_ (abundant as a coral reef organism), _Hydractinia_ (parasitic on shells, etc.), and _Sertularia_ (Sea-firs).

=Milleporids and Stylasterids.--=

Although so abundant at the present time, the genus _Millepora_ does not date back beyond the Pleistocene. The Eocene genus _Axopora_ is supposed to belong here, but is not Australian. Of the Stylasterids one example is seen in _Deontopora_, represented by the branchlets of _D. mooraboolensis_, from the Janjukian limestone of the Moorabool Valley, near Geelong.

=Hydractinia.--=

_Hydractinia_ dates from the Upper Cretaceous rocks in England, and in Australia its encrusting polypidom is found attached to shells in the polyzoal limestone of Mount Gambier (Miocene).

Stromatoporoids.

An important group of reef-builders in Palaeozoic times was the organism known as _Stromatopora_, and its allies. The structures of these hydroid polyps resemble successional and repetitional stages of a form like _Hydractinia_. As in that genus it always commenced to grow upon a base of attachment such as a shell, increasing by successive layers, until the organic colony often reached an enormous size, and formed great mounds and reefs (see _antea_, Fig. 32). The stromatoporoid structure was formed by a layer of polyp cells separated by vertical partitions, upon which layer after layer was added until a great vertical thickness was attained. This limestone-making group first appeared in the Silurian, and probably reached its maximum development in Middle Devonian times, when it almost disappeared, except to be represented in Carbopermian strata by a few diminutive forms.

A--Actinostroma clathratum, Nich. Devonian. Rough Range, W.A.

B--Actinostroma clathratum, Nich. Devonian. Rough Range, W.A. Vertical
section.

(_After G. J. Hinde_).

C--Callograptus sp. Up. Ordovician. San Remo, Vict.

(_After T. S. Hall_).

D--Ptilograptus sp. Up. Ordovician. San Remo, Vict.

(_After T. S. Hall_).

E--Dictyonema pulchellum, T. S. Hall. L. Ordov. Lancefield, Vict.

F--Dictyonema macgillivrayi, T. S. Hall. L. Ordov. Lancefield, Vict.

]

=Silurian Stromatoporoids.--=

In the Silurian limestones of Victoria (Lilydale, Waratah Bay, Walhalla and Loyola), and New South Wales (near Yass), Stromatoporoids belonging to the genera _Clathrodictyon_ (probably _C. regulare_), _Stromatopora_ and _Idiostroma_ occur. _Stromatoporella_ has been recorded from the Silurian rocks of the Jenolan Caves, New South Wales.

=Devonian Stromatoporids.--=

The Middle Devonian strata of Bindi, Victoria, yield large, massive examples of _Actinostroma_. This genus is distinguished from the closely allied _Clathrodictyon_ by its vertical pillars passing through several laminae in succession. Rocks of the same age in Queensland contain _Stromatopora_, whilst in Western Australia the Rough Range Limestone has been shown to contain _Actinostroma clathratum_ (Fig. 72 A, B) and _Stromatoporella eifeliensis_.

Cladophora.

=Palaeozoic Cladophora.--=

Some branching and dendroid forms of Hydrozoa probably related to the modern Calyptoblastea ("covered buds"), such as _Sertularia_ and _Campanularia_, are included in the Cladophora ("Branch bearers"). They existed from Cambrian to Devonian times, and consist of slender, forking branches sometimes connected by transverse processes or dissepiments, the branches bearing on one or both sides little cups or hydrothecae which evidently contained the polyps, and others of modified form, perhaps for the purpose of reproduction. The outer layer, called the periderm was of chitinous material. They were probably attached to the sea-floor like the Sertularians (Sea-firs).

=Dictyonema and Allies.--=

Remains of the above group are represented in the Australian rocks by several species of _Dictyonema_ (Fig. 72 E, F) occurring in the Lower Ordovician of Lancefield, and in similar or older shales near Mansfield. Some of these species are of large size, _D. grande_ measuring nearly a foot in width. The genera _Callograptus_, _Ptilograptus_ (Fig. 72 C, D) and _Dendrograptus_ are also sparsely represented in the Upper Ordovician of Victoria, the two former from San Remo, the latter from Bulla.

Graptolites (Graptolitoidea).--

=Value of Graptolites to Stratigraphist.--=

The Graptolites were so named by Linnaeus from their resemblances to writing on the slates in which their compressed remains are found. They form a very important group of Palaeozoic fossils in all parts of the world where these rocks occur, and are well represented in Australasia. The species of the various Graptolite genera are often restricted to particular beds, and hence they are of great value as indicators of certain horizons or layers in the black, grey or variously coloured slates and shales of Lower Ordovician to Silurian times. By their aid a stratum or set of strata can be traced across country for long distances, and the typical species can be correlated even with those in the older slates and shales of Great Britain and North America.

=Nature of Graptolites.--=

The Graptolites were compound animals, consisting of a number of polyps inserted in cups or thecae which budded out in a line from the primary sicula or conical chamber, which chamber was probably attached to floating sea-weed, either by a fine thread (nema), or a disc-like expansion. This budding of the polyp-bearing thecae gives to the polypary or colony the appearance of a fret-saw, with the teeth directed away from the sicula.

The habit of the earlier graptolites was to branch repeatedly, as in _Clonograptus_, or to show a compound leaf-like structure as in _Phyllograptus_. Later on the many-branched forms had their branches reduced until, as in _Didymograptus_, there were only two branches. Sometimes the branches opened out to direct the thecae upwards, the better to procure their food supply. In _Diplograptus_ the thecae turned upwards and acquired a support by the formation of a medium rod (virgula), often ending in a disc or float. In Silurian times _Monograptus_ prevailed, a genus having only a single row of thecae supported by a straight or curved virgula. In _Retiolites_ the polypary opened out by means of a net-work of fine strands, rendering it better able to float, at the same time retaining its original strength.

=Lower Ordovician Graptolites, Victoria.--=

The Lower Ordovician slates and shales of Victoria have been successfully divided into several distinct series by means of the Graptolites. These, commencing at the oldest, are:--

(1) Lancefield Series. Characterised by _Bryograptus clarki_, _B. victoriae_, _Didymograptus pritchardi_, _D. taylori_ and _Tetragraptus decipiens_. Other forms less restricted are, _Clonograptus magnificus_ (measuring over a yard in breadth), _C. flexilis_, _C. rigidus_, _Leptograptus antiquus_ and _Tetragraptus approximatus_ (Fig. 73).

(2) Bendigo Series. Characterised by _Tetragraptus fruticosus_, _T. pendens_, _Trichograptus fergusoni_ and _Goniograptus thureaui_. This series also contains _Tetragraptus serra_ (ranging into Darriwill Series), _T. bryonoides_, _T. quadribrachiatus_, _T. approximatus_ (base of the series), _Phyllograptus typus_, _Dichograptus octobrachiatus_, _Goniograptus macer_ and many _Didymograpti_, including _D. bifidus_ (Fig. 74).

A--Bryograptus clarki, T. S. Hall. L. Ordovician. Lancefield, Vict.

B--Tetragraptus fruticosus, J. Hall sp. L. Ordovician. Lancefield.

C--Phyllograptus typus, J. Hall. L. Ordovician. Lancefield.

D--Goniograptus macer, T. S. Hall. L. Ordovician. Lancefield.

E--Didymograptus caduceus, Salter. L. Ordovician. Lancefield.

F--Trigonograptus wilkinsoni, T. S. Hall. L. Ordov. Darriwill, Vict.

]

A--Loganograptus logani, J. Hall sp. L. Ordov. Newham, Vict.

B--Tetragraptus approximatus, Nich. L. Ordovician. Canada and Victoria.

(_After Nicholson_)

C--Tetragraptus serra, Brongn. sp. L. Ordovician. Lancefield, Vict.

D--Didymograptus bifidus, J. Hall. L. Ordovician. Guildford, Vict.

]

(3) Castlemaine Series. Characterised by _Didymograptus bifidus_, _D. caduceus_ and _Loganograptus logani_. _Phyllograptus_ persists from the Bendigo Series. It also contains _Tetragraptus serra_, _T. bryonoides_, _T. quadribrachiatus_, _Goniograptus macer_ and several _Didymograpti_.

(4) Darriwill Series. Characterised by _Trigonograptus wilkinsoni_. Also contain _Diplograptus_, _Glossograptus_ and _Lasiograptus_, whilst _Didymograptus_ is rare.

=Lower Ordovician Graptolites, New Zealand.--=

In New Zealand Lower Ordovician Graptolites are found in the Kakanui Series, at Nelson, north-west of South Island. Some of the commoner forms are _Didymograptus extensus_, _D. caduceus_, _Loganograptus logani_, _Phyllograptus typus_, _Tetragraptus similis_ and _T. quadribrachiatus_.

Graptolites agreeing closely with those of the Lancefield Series of Victoria occur near Preservation Inlet in the extreme South-west, and have been identified as _Clonograptus rigidus_, _Bryograptus victoriae_ and _Tetragraptus decipiens_.

=Upper Ordovician Graptolites, Victoria.--=

The Upper Ordovician rocks of Victoria, as at Wombat Creek and Mount Wellington in Gippsland, and at Diggers' Rest near Sunbury, contain the double branched forms like _Dicranograptus ramosus_, _Dicellograptus elegans_ and _D. sextans_; the sigmoidal form _Stephanograptus gracilis_; and the diprionidian (biserial) forms as _Diplograptus tardus_, _Climacograptus bicornis_, _Cryptograptus tricornis_, _Glossograptus hermani_ and _Lasiograptus margaritatus_ (Fig. 75).

A--Dicranograptus ramosus, J. Hall sp. Up. Ordovician. Victoria.

B--Dicellograptus elegans, Carruthers sp. Up. Ordovician. Victoria.

C--Diplograptus carnei, T. S. Hall. Up. Ordovician. N. S. Wales.

D--Climacograptus bicornis, J. Hall. Up. Ordovician. Victoria.

E--Glossograptus hermani, T. S. Hall. Up. Ordovician. Victoria.

F--Retiolites australis, McCoy. Silurian. Keilor, Victoria.

G--Monograptus dubius, Suess. Silurian. Wood's Point, Victoria.

]

=Upper Ordovician Graptolites, New South Wales.--=

In New South Wales, at Tallong, the Upper Ordovician Graptolites are well represented by such forms as _Dicellograptus elegans_, _Dicranograptus nicholsoni_, _Diplograptus carnei_, _D. foliaceus_, _Cryptograptus tricornis_ and _Glossograptus quadrimucronatus_, etc. Other localities in New South Wales for this Graptolite fauna are Stockyard Creek, Currowang, Tingaringi, Lawson, and Mandurama.

=Tasmania.--=

From Tasmania a _Diplograptus_ has been recorded, but the particular horizon and locality are uncertain.

=Silurian Graptolites, Victoria.--=

In the Silurian shales at Keilor, in Victoria, _Monograptus_ is a common genus, and _Cyrtograptus_ and _Retiolites australis_ (Fig. 75 F) also occur. Several species of _Monograptus_ have also been found at South Yarra and Studley Park. At the latter place and Walhalla _Monograptus dubius_, which is a Wenlock and Ludlow fossil in Britain, has been found in some abundance (Fig. 75 G).

* * * * *

COMMON OR CHARACTERISTIC FOSSILS OF THE FOREGOING CHAPTER.

SPONGES.

_Protospongia_ sp. Cambrian: S. Australia.

_Hyalostelia_ sp. Cambrian: S. Australia.

_Protospongia oblonga_, Hall. L. Ordovician: Victoria.

_Stephanella maccoyi_, Hall. L. Ordovician: Victoria.

_Carpospongia_ sp. Silurian: Yass, New South Wales.

_Receptaculites fergusoni_, Chapman. Silurian: Victoria.

_Receptaculites australis_, Salter sp. Devonian: Victoria and New
South Wales. Carboniferous: Queensland.

(?) _Lasiocladia hindei_, Eth. fil. Carbopermian: Queensland.

_Purisiphonia clarkei_, Bowerbank. Lower Cretaceous: Queensland.

_Geodia_ sp. Cainozoic: W. Australia.

_Tethya_ sp. Cainozoic: W. Australia.

_Ecionema newberyi_, McCoy sp. Cainozoic: Victoria.

_Plectroninia halli_, Hinde. Cainozoic (Janjukian): Victoria.

_Tretocalia pezica_, Hinde. Cainozoic (Janjukian): Victoria.

ARCHAEOCYATHINAE.

_Protopharetra scoulari_, Etheridge, fil. Cambrian: S. Australia.

_Coscinocyathus australis_, Taylor. Cambrian: S. Australia.

_Archaeocyathina ajax_, Taylor. Cambrian: S. Australia.

CORALS.

_Cyathophyllum approximans_, Chapman. Silurian: Victoria.

_Tryplasma liliiformis_, Etheridge, fil. Silurian: New South Wales.

_Favosites grandipora_, Etheridge fil. Silurian: Victoria.

_Pleurodictyum megastomum_, Dun. Silurian: Victoria.

_Halysites peristephicus_, Etheridge, fil. Silurian: New South Wales.

_Heliolites interstincta_, Linné sp. Silurian: Victoria.

_Campophyllum gregorii_, Eth. fil. Middle Devonian: Victoria and
Queensland.

_Cystiphyllum australasicum_, Eth. fil. Middle Devonian: New South
Wales and Queensland.

_Favosites multitabulata_, Eth. fil. Middle Devonian: Victoria and New
South Wales.

_Pachypora meridionalis_, Eth. fil. Middle Devonian: Queensland.

_Zaphrentis culleni_, Eth. fil. Carboniferous: New South Wales.

_Lophophyllum corniculum_, de Koninck. Carboniferous: New South Wales.

_Zaphrentis profunda_, Eth. fil. Carbopermian: Queensland.

_Campophyllum columnare_, Eth. fil. Carbopermian: New South Wales.

_Trachypora wilkinsoni_, Eth. fil. Carbopermian: New South Wales.

_Stenopora tasmaniensis_, Lonsdale. Carbopermian: Tasmania and New
South Wales.

_Flabellum gambierense_, Duncan. Cainozoic: Victoria, S. Australia and
Tasmania.

_Placotrochus deltoideus_, Duncan. Cainozoic: Victoria, S. Australia
and Tasmania.

_Sphenotrochus emarciatus_, Duncan. Cainozoic: Victoria, S. Australia,
and Tasmania.

_Ceratotrochus exilis_, Dennant. Cainozoic: Victoria.

_Conosmilia elegans_, Duncan. Cainozoic: Victoria.

_Balanophyllia armata_, Duncan. Cainozoic: Victoria.

_Thamnastraea sera_, Duncan. Cainozoic: Victoria and Tasmania.

_Graphularia senescens_, Tate sp. Cainozoic: Victoria and S. Australia.

HYDROZOA.

_Clathrodictyon_ (?) _regulare_, Rosen sp. Silurian: Victoria.

_Actinostroma clathratum_, Nicholson. Devonian: W. Australia.

_Stromatoporella eifeliensis_, Nich. Devonian: W. Australia.

_Dictyonema pulchella_, T. S. Hall. Lower Ordovician: Victoria.

_Ptilograptus_ sp. L. Ordovician: Victoria.

_Callograptus_ sp. Lower Ordovician: Victoria.

GRAPTOLITES.

_Bryograptus victoriae_, T. S. Hall. Lower Ordovician (Lancefield
Series): Victoria.

_Tetragraptus fruticosus_, J. Hall. L. Ordovician (Bendigo Series):
Victoria.

_Didymograptus caduceus_, Salter. L. Ordovician (Castlemaine Series):
Victoria. Also New Zealand.

_Didymograptus bifidus_, J. Hall. L. Ordovician (Castlemaine Series):
Victoria. Also New Zealand.

_Trigonograptus wilkinsoni_, T. S. Hall. L. Ordovician (Darriwill
Series): Victoria.

_Dicranograptus ramosus_, J. Hall sp. Upper Ordovician: Victoria.

_Monograptus dubius_, Suess. Silurian: Victoria.

_Retiolites australis_, McCoy. Silurian: Victoria.

* * * * *

LITERATURE.

SPONGES.

Cambrian.--Tate, R. Trans. R. Soc. S. Austr., vol. XV. (N.S.), 1892,
p. 188.

Ordovician.--Hall, T. S. Proc. R. Soc. Vict., vol. I. pt. I. 1889, pp.
60, 61 (_Protospongia_). Idem, ibid., vol. XI. (N.S.), pt. II.
1899, pp. 152-155 (_Protospongia and Stephanella_).

Silurian to Carboniferous.--Salter, J. W. Canad. Org. Rem. Dec. I.
1859, p. 47. Etheridge, R. jnr. and Dun, W. S. Rec. Geol. Surv.
New South Wales, vol. VI. 1898, pp. 62-75. Chapman, F. Proc. R.
Soc. Vict. vol. XVIII. (N.S.), pt. 1, 1905, pp. 5-15.

Carbopermian.--Etheridge, R. jnr., in Geol. and Pal. Q., 1892, p. 199.

Cretaceous.--Bowerbank, J. S. Proc. Zool. Soc. Lond., 1869, p. 342.
Etheridge, R. jnr. in Geol. and Pal. Queensland, 1892, pp. 438,
439 (_Purisiphonia_).

Cainozoic.--McCoy, F. Prod. Pal. Vict., Dec. V. 1877. Chapman, F.
Proc. R. Soc. Vict., vol. XX. (N.S.), pt. 2, 1908, pp. 210-212
(_Ecionema_). Hinde, G. J. Quart. Journ. Geol. Soc., vol. LVI.,
1900, pp. 50-56 (calcisponges). Idem, Bull. Geol. Surv. W.
Austr., No. 36, 1910, pp. 7-21 (sponge-spicules).

ARCHAEOCYATHINAE.

Etheridge, R. jnr., Trans. R. Soc. S. Austr., vol. XIII. 1890, pp.
10-22. Taylor, T. G. Mem. Roy. Soc. S. Austr., vol. II., pt. 2,
1910 (a monograph).

CORALS.

Silurian.--Etheridge, R. jnr. Rec. Geol. Surv. New South Wales, vol.
II. pt. 1, 1890, pp. 15-21 (Silurian and Devonian). Idem, ibid.,
vol. II. pt. 4, 1892, pp. 165-174 (Silurian and Devonian). Idem,
in Pal. and Geol. Queensland, 1892. Idem, Rec. Austr. Mus., vol.
I., No. 10, 1891, pp. 201-205 (_Rhizophyllum_). Id., ibid., vol.
III. No. 2, 1897, pp. 30-33 (_Columnaria_). Id., Prog. Rep. Geol.
Surv. Vict., No. 11, 1899, pp. 30-36. Idem, Mem. Geol. Surv. New
South Wales, No. 13, pt. I., 1904 (_Halysites_). Id., ibid., No.
13, pt. 2, 1907 (_Tryplasma_). De Koninck, L. G. ibid., Pal. No.
6, 1898. Shearsby, A. J. Geol. Mag., Dec. V., vol. III. 1906,
pp. 547-552. Chapman, F. Rec. Geol. Surv. Vict., vol. II. pt. 1,
1907, pp. 67-80.

Devonian.--Etheridge, R. jnr. and Foord, A. H. Ann. Mag. Nat.
Hist., ser. V., vol. XIV., 1884, pp. 175-179 (_Alveolites_ and
_Amplexopora_ = _Litophyllum_). Etheridge, R. jnr., in Geol. and
Pal. Queensland, 1892. Idem, Proc. Linn. Soc. New South Wales,
vol. IX. 1895, pp. 518-539. Id., Rec. Geol. Surv. New South
Wales, vol. VI. pt. 3, 1899, pp. 152-182 (Tamworth District).
Id., Rec. Austr. Mus., vol. IV. No. 7, 1902, pp. 253-260. De
Koninck, L. G. Mem. Geol. Surv. New South Wales, Pal. No. 6,
1898. Chapman, F. Rec. Geol. Surv. Vict., vol. III, pt. 2, 1912,
pp. 215-222.

Carbopermian.--Etheridge, R. jnr. Mem. Geol. Surv. New South Wales,
Pal. No. 5, 1891. Idem, in Geol. and Pal. Queensland, 1892. Id.,
Bull. Geol. Surv., W. Austr., No. 10, 1903, pp. 8-10.

Cainozoic.--Duncan, P. M. Quart. Journ. Geol. Soc., vol. XXVI. 1870,
pp. 284-318; vol. XXXI. 1875, pp. 673-678; vol. XXXII. 1876, pp.
341-351. Woods, T. Proc. Linn. Soc. New South Wales, vol. XI.,
1878, pp. 183-195; ibid., vol. XXX. 1879, pp. 57-61. Idem, Trans.
Roy. Soc. S. Austr., vol. I., 1878, pp. 104-119. Dennant, J.
Trans. R. Soc. S. Austr., vols. XXIII. (1899) to XXVIII. (1904).

STROMATOPOROIDS.

Hinde, G. J. Geol. Mag., Dec. III. vol. VII, 1890, p. 193.

GRAPTOLITES.

McCoy, F. Prod. Pal. Vict., Decades I. (1874): II. (1875): V. (1877).
Hall, T. S. Proc. Roy. Soc. Vict., vol. IV. p. I. 1892, pp. 7,
8 (_Dictyonema_). Idem, Geol. Mag. Dec. IV. vol. VI. 1899, pp.
438-451; Id., Rep. Austr. Assoc. Adv. Sci., Brisbane, 1909, pp.
318-320. Id., Rec. Geol. Surv. Vict., vol. I. pt. 4, 1906, pp.
266-278. Id., ibid., vol. III. pt. 2, 1912, pp. 188-211. Idem,
Rec. Geol. Surv. New South Wales, vol. VII. part 1, 1910, pp. 16,
17. Ibid., pp. 49-59.