84 
Horizon and Localities . — This species has heen sent to me hy Mr. 
Clarke under the name in which I have just described it, and was collected hy 
him in a compact blackish limestone from the Yass District; also atDuntroon, 
in a yellow-brown argillaceous limestone, softer than the first, in which it is 
more common. 
5. Spirifeu latisinuatus, L. G. de Koninck. 
PI. Ill, Pig. 7. 
Spirifer curvatus, var. undldata ? C. P. Eoemer, 1814, Das Eheiu. Uebergangsgebirge, 
p. 70, PI. 4, Pig. 5, non Scbl. 
Shell gibbous, broad, widest at the Iiingeline. Ventral valve provided 
with a broad sinus that occupies at the margin almost half the valve, rather 
deep and hollowed in the form of a canal with a rounded bottom. The beak, 
which I know hut imperfectly, appears to be well developed and a little 
curved on itself ; the area is rather high and triangular. The dorsal valve 
is suh-semi-circular, slightly sinuated in the frontal portion, and provided 
with an obtuse rather prominent fold. The sides of each of the valves 
are ornamented with seven or eight radiating ribs of an almost equal 
thickness, and which are only sejDarated from one another hy very slightly 
marked furrows. The well-preserved portions of the shell are covered, 
principally towards the margins, with fine concentric lamellce. 
Dimensions. — Length, twenty-two millimetres ; breadth, thirty milli- 
metres ; thickness, eighteen millimetres ; width of the sinus, fourteen milli- 
metres. 
Relations and Differences. — I am strongly of opinion that the 
I have just described is identical with that which Mr. Ferd. Foemer has 
figured under the name Sp. curvatus, Schlotheim, hut which has no analogy 
to that species. It resembles more, in the form of the folds, S. cahanillas, 
de Verneuil, from which, however, it may he easily separated hy its broad 
shape, while that of the Spanish form is elongate and almost oval. 
Horizon and Localities. — Spirifer latisinuatus is found on the hanks 
of the Murrumhidgce, in the Yass District, in a blackish, very compact lime- 
stone, and also in the Middle Devonian limestone of Gerolstein in the Eifel. 
