233 
much grooved and ridged ; shelly plates large, strong, and thick ; dental plates large, 
extending outwards and downwards; adductor sears comparatively small, much 
elongated ; cardinal im])ressions large, elongate, festoonly ridged. Dorsal valve 
angularly convex, much produced along the middle line of the fold, which is sharp and 
angular ; umbo projecting above the area. Ornament of the valves very characteristic, 
the flanks in both bearing four or five rough-looking costa?, each composed of two to five 
subsidiary ribs, the bifurcation taking place at about one-third from the umbones ; the 
fold bears three slightly elevated costae on each side, and the sinus is similarly divided, 
the whole being crossed by concentric distant, wavy, and strong imbricating lamella? of 
growth. 
Ohs. The size, form, and coarse ornament are the chief points worthy of notice 
lu S. SioJeesii. The interspaces between the groups of cost®, sometimes, although rarely, 
carry smaller and subsidiary ribs. The wings are traversed by flattened, close ribs, 
similar to the latter, but they do not project like those on the bodies of the valves. On 
the ventral valve the cost® appear at times to bo less split up than those of the dorsal, 
Until contiguous to the front margin. Prof. Morris’s description is very characteristic 
of the species. He says — “ A rough- looking species in consequence of the paucity and 
®ize of the lateral ribs, the central one being still prominent.” 
Spirifera Slokesii is probably the largest of the Australian radiate Spirifers, and 
belongs to the same group as Spirifera duplioicosta, Phill.,* of the Eurojiean Carboni- 
ferous, and which possesses similar tripartite cost®. The best figure of this species with 
■'vhich I am acquainted is D’Orbigny’s. In this illustration there are three large divided 
ribs on each flank, and the interspaces filled as previously described. The fold has 
three ribs on each side. 
Spirifera Keillmvii, Von Buch, has coarse angular ribs like our species, but the 
form of the shell is quite different. 
Loc. and Horizon. Glympie — GympieBeds; Banana Creek, near Banana, Dawson 
liver — Middle or Marine Series of the Bowen Eiver Coal Pield ; Yatton Gold Yield 
(■n. L. Jack ) — Gympie Beds; Eichards’ Homestead, three miles south-west of Mount 
ritton Tow'nship (^Messrs. A. L. JiLorisset and if. Hull ) — Middle or Marine Series 
°f the Bowen lliver Coal Pield. 
Spieifeea pinguis, J. Sowerhy. 
^^rifer pinguis, J. Sowerby, -Min. Con., 1820, iii., p. 125, t. 271. 
Pirfcra pinguis, Davidson, Mon. Brit. Garb. Braoh, 18.58, Pt. 2, p. 50, t. 10, f. 1-12. 
■Pui/cr pinguU, var. rotimilatus, De Koninok, Foss. Pal. iSfouv.-Galies du Sud, 1877, Pt. 3, p. 238, t. 11, 
f. 2, 2a. 
^ Ohs. Numerous examjiles of a rather small species occur in the altered rocks 
° the Roekham])ton District, none actually perfect, but, as far as preserved, closely 
^®'’®bbng some of Davidson’s figures of the above speeio.s, particularly his figs. 1-3. 
e ribs are rounded, one or two indistinct ones occupying the sinus, whilst the fold is 
V ‘ in. Over and above this, the specimens, although imperfect, have that indescribably 
Du and rotundly-radiate appearance which always accompanies this species, 
^"vidsou remarks on Spirifera pinffuis — “Very variable in shape, dimensions, relative 
uportions, and degree of convexity,” and the present shells may well come within this 
category. 
P, -£oc. and Horizon. Eockhampton District f (O. W.DeVis; Colin. De Vis)— ■ 
^yuipie Beds. 
■* See Davidson’ s Mon. Brit. Garb. Brack., 1857, Pt. i, t. 4, f. 4. 
t See note, p 199. 
