ANATINIDA. 153 
Nemromya, Gabb, 1872. 
Distr.—N. quadrata, Gabb (eviii, 78-80). Tertiary; West 
Indies. 
Shell thin, translucent, in shape approaching Pholadomya, 
ends closed; hinge with a prominent tooth in the right valve, 
articulating behind a smaller similar one in the left valve; an 
anterior and posterior lateral tooth in each valve ; mantle-margin 
without sinus. 
This genus, in its thin character and minute hinge, is closely 
allied to Pholadomya, Thetis, and Nera, but differs from all in 
the details of the hinge. Nezera has no cardinal tooth, but in 
its place a cartilage-pit in each valve; it has a single posterior 
tooth, while this genus has the anterior equally well-developed. 
In having corresponding teeth in both valves it differs from 
Thetis, while its well-specialized hinge and its closed ends dis- 
tinguish it from Pholadomya. 
Ostomya, Conrad, 1874. 
Distr.—O. papyria, Conr. (eviii, 81, 82.. Tertiary; Upper 
Amazon. 
Shell thin, concentrically plicate; hinge with a spoon-shaped 
oblique fosset in the left valve, and a small tooth near the apex ; 
right valve cartilage-fosset very oblique, almost parallel with the 
hinge-line. 
TeLLinopsis, Hall, 1869. 
Syn.—Tellinites, M’Coy (part). 
Distr.—T. subemarginata, Conv. (eviii, 83. Fossil. Hamilton 
Group, New York. 
Shell thin, fragile, general form of Tellina, with moderately 
convex valves, small subcentral beaks, having their apices 
directed backwards with a shallow posterior furrow; hinge 
apparently edentulous; ligament external, small; muscular 
impression very faint, situated near the cardinal extremity ; pal- 
lial line undetermined. 
SANGUINOLITES, M’Coy, 1844. 
Syn.—Cypricardites, Conr., 1841 (part). 
Distr.—Carbon.; Eur. 8S. discors, M’Coy. 
Very elongated, with subparailel upper and lower margins, 
rounded anteriorly, obliquely truncate posteriorly, with an 
oblique prominent ridge from the beaks to the postero-inferior 
margin, very inequilateral, beaks slightly prominent, close 
together, subanterior; anterior muscular impression oval, 
distinct, with a small groove above it, and both posteriorly 
bounded by a prominent ridge, posterior muscular scar faint ; 
cardinal margin internally thickened the whole length, probably 
for the support of a ligament; surface concentrically (or 
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