Fossils from Australia. 157 
pressions which belong together, to each valve, as in Corbis. From 
the impression of the hinge of a left valve, there appear t 0 prom- 
inent teeth; it has a very oblique shallow sulcus, directed posteriorly 
from the centre of the hinge, and a slight excavation anterior to the 
centre. ‘‘he form is more transverse and the teeth less distinct 
than in Cordis. It has not the long lunate muscular impression of 
Lucina. 
31. Pyramus eilipticus.—Oblong, length half greater than —- 
lower margin arcuate, sides evenly convex, surface strongly but 
evenly marked with regular concentric strie, posterior and large on 
rior muscular impressions rather indistinct, not excavate ; palleal im- 
pression eat and posterionly plicatulate. Cast of beak acute at 
apex.—Length 13 inch; height =4% L; thickness 444 L; apical angle 
187°. Another specimen, probably same species, three inches long.— 
wehtag s Hill. 
Pyramus myiformis.—Oblong, length two- — greater than 
nr ig exterior smooth, with faint strie of grow lower margin 
nearly straight, lateral surface below somewhat Sasade muscular im- 
pressions distinct, posterior not excavate, large anterior a little so above, 
smaller anterior dee eply excavate, and the surface of attachment facing 
the same way with the larger; palleal impression faint. Cast having 
the beak terminate in a minute cylinder, and having the lateral sur- 
face, from the summit crbtiegnely downward and backward, depressed. 
—Length 2 inches; height 35 L; — about 7% L; apical an- 
gle 148° or 150°. The front and posterior margin are more road|. 
rounded than in the idee the lower margin straiter, the apical an- 
gle much larger.—ZJllawa 
33. Nucula hempiastichs elongate, transverse, rather abruptly 
narrowing behind the summit, and diminis ing posteriorly ; ' posterior 
orsal margin much concave; anterior margin rounded ; cast strongly 
ness +49; or 
= eat os a muscle, about half greatest eight.—lawarra 
34. Nu mee 
anterior part one- 
35. Cyp ong transverse, 
third wel: ot narrowing rather abruptly from the beak posterior- 
ly, posterior surface (flank) broad and flat truncate, with a carinate 
ness 33, L; apical an le or. Wlawebr 
ear ae tog to ante, anterior part about 2 
whole length; posterior rather rapidly narrowing but not abruptly; 
a 
