PERMO-CARBONIFEROUS PELECYPODA — ETHERIDGE. 
181 
(Compare Cypricardia ( Avicula? ) veneris, Dana, loc. cit., pi. 9, f. 3, 
3 a and b.) 
Sp. Char. — Shell more or less compressed pod- or filbert-shaped, 
very inequilateral ; dorsal and ventral margins almost parallel, 
the former straight, and the latter but little curved, with a slight 
inflection at about its anterior third ; no diagonal ridges, but the 
valves uniformly and very slightly convex throughout, except for 
shallow cinctures running obliquely from the umbones posteriorly 
to the ventral margins ; umbones inconspicuous, depressed. 
Anterior ends very small, slightly protruding, the margins rounded; 
posterior ends compressed, the margins obliquely rounded above 
and below. Ligamental fulcra large, leaving deep impressions in 
casts ; ligamental (?) pits transversely elongated, inclined to tri- 
angular, represented in casts by sharp crests. Anterior adductor 
impressions very large, rather deltoid, concentrically grooved, the 
thickened posterior edges leaving wide groove-like depressions in 
casts, which extend to immediately in front of the umbones. Six- 
teen to twenty radiating costre proceed from the umbones to the 
posterior margins commencing just behind the shallow oblique 
cinctures, with the whole surface crossed by close concentric fine 
lines, which imbricate the costte. 
Obs. — As this was the first species described by Morris, it must 
be regarded as the type. His fig. 1, of the reference quoted above, 
gives a faithful and accurate representation of the shell, and it 
will be observed that the radiating costse are there visible on the 
cast, the test having broken away along the hinge line in both 
valves. Fig. 2 is an equally good illustration, but on this, although 
again a cast, the coste are not visible at all. In DeKoninck’s 
figure of this species the umbones are too acute and projecting, as 
they do not in reality overhang the anterior ends. 
There appears to be every probability of Dana’s Cypricardia 
(Avicula ? ) veneris being nothing more than a small individual 
of this species. 
Loc. and Hor. — Jamberoo, Black Head, and Crooked River, 
near Gerringong, Illawarra District— Upper Marine Series. 
Stutciiburia compressa, Morris , sp. 
(PI. xxxi., fig. 2, and xxxiii., fig. 1.) 
Orthonota ( \ costata , Morris, loc. cit., pi. 11, fig. 2, (non f. 1) 
Orthonotah compressa, Morris, loc. cit., p. 274, pi. 13, f. 4. 
Orthonota compressa , Eth. fil., loc, cit., p. 74. 
Obs. — The specific value of this form mainly depends on the 
presumed absence of the posterior radiate sculpture, but as this is 
seen on one of Morris’ types of S. costata , and not on the other, it 
may be taken as a specific character. I have therefore included 
the figure without the posterior radii as a synonym of S. compressa , 
