O44. PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 
length of the shell; umbones depressed; ventral area extended ; 
deltidium narrow, triangular; exterior of the valves covered with 
coarse rounded strive, which are broken at the concentric lines of 
growth, where they are seen to be hollow, and were probably con- 
tinued in spines over the folds of the shell; exterior of dorsal valve 
abruptly keeled, the lines of growth crossing, which give the keel a 
comb-like appearance ; interior of the dorsal valve with a sinus, 
which terminates at the front of the shell in a deep fold; andit pos- 
sesses teeth-sockets, cardinal process, and distinctly raised crural 
plates ; ventral valve, in its younger state, rather flat, but becomes 
concare and closely fitting to the dorsal valve; it possesses a deep sinus 
corresponding to the depression in the interior of the large valve ; 
edges of the shell closely fitting ; internal loop not known. 
Shell-structure very finely punctated. This interesting shell is 
found with the Purisiphonia and other remains at Wollumbilla ; and 
as there are evidences of several more or less perfect examples in the 
block, it must be an abundant shell. It belongs to the group ori- 
ginally arranged by Dr. EK. Deslongchamps under Argyope, of which 
he described three species from the Lias, but which, in his ‘ Paléon- 
tologie Francaise,’ he subsequently removed to Verebratula. Having 
found the same species at Whatley, and referred them to Argyope, I 
think it convenient still to retain them in this group, though ulti- 
mately it is probable they may have to be separated from it and con- 
stituted a subgenus. At present little is known of their loops or 
internal characters. The Australian examples are more regularly 
striate than the Kuropean Liassic species. Where the striz on the 
A. wollumbillaensis are occasionally abraded, a canal is visible, which 
leads me to suspect they were originally hollow, and probably con- 
tinued in spines beyond the shell, like those on Athyris or Spirifera 
rostrata. In its outer form this shell very much resembles some of 
the Strophomenide. 
7. ARGYOPE PuNCTATA, sp.n. PI. X. fig. 6. 
Shell small, transversely ovate; dorsal valve flattened or slightly 
convex ; margins regularly rounded; surface of valve with bifur- 
cating longitudinal striee, which at the front are thirty in number. 
This shell clearly indicates the presence of a second species of this 
group. Only one valve is known, and this is not perfect. The 
strie are much more distant, and stand up in sharp ridges, and the 
punctations are much coarser and fewer than on the A. wollumbil- 
laensis. In these respects the species approaches nearer to the French 
and English examples. 
The specimen is from Wollumbilla, and is attached to the surface 
of a Serpula intestinalis ? 
8. Discrna apicatis, sp.n. Pl. X. fig. 13. 
Shell small, round or slightly ovate; apex very acute, almost 
central, or inclined to anterior end; shell-structure thin, with faint 
concentric lines of growth. 
I have only seen a single, somewhat imperfect, example of this 
