KNOWN SPECIES OF MARINE OSTRACODA. 387 
aspect oval, fully twice as long as broad, pointed in front, mucronate behind. Surface 
smooth, white. 
Length 3); in. (2 mm.). 
Hab. Pescadore, China. ‘Taken in the towing-net (Mr. A. Adams). 
3. Cypripina BAIRDII, n. sp. (Pl. LXII. fig. 7, a—m.) 
Carapace horny, suborbicular, convex, about one-third longer than broad, obtusely 
mucronate posteriorly, flattened in front, Dorsal and ventral margins convex, uniting 
behind to form a rather broad, obtuse, terminal spine. The anterior margin is sulcate 
in the middle. Beak short and broad; notch rather small. Seen from the ventral 
surface, the outline of the carapace is oval, oblong ; its anterior extremity truncate, 
posterior subacute. End view oval, with broad, truncate extremities. The right valve 
bears on its ventral margin, a little in front of the beak, a rounded prominence, which 
is absent from the left valve. The left valve is, however, larger and more rounded in 
outline, so that it overlaps the projections of the opposite valve much in the same way 
as the large and rounded valve of Bazrdia overlaps the smaller and angular one. Surface 
‘ornamented with large and thickly set circular pits, which, on the ventral and dorsal 
aspects, coalesce so as to form jagged furrows. 
Length 5 in. (2°54 mm.). 
Hab. Pescadore, China. Many specimens taken in the towing-net (Mr. A. Adams). 
Genus HEreRopEsMus, nov. gen. 
Carapace subglobose. Dorsal margin slightly arched, forming at its extremities two 
largely developed hinge-processes ; the anterior process somewhat waved and scroll- 
like; the posterior a truncate cone, projecting directly upwards. Ventral margin 
strongly arched. Animal unknown. 
HETERODESMUS ADAMSII, n.sp. (PI. LXII. fig. 6, a-h.) 
Carapace subquadrilateral, convex ; length about one-fourth greater than the breadth. 
Ventral margin prominently arched. Dorsal margin slightly arched, terminating pos- 
teriorly in a strong, truncated, conical process, which projects upwards beyond the plane 
of the dorsum. The anterior hinge-process forms a swollen, scroll-like protuberance 
situated at the upper angle of the anterior margin, and hollowed out beneath so as to 
form a somewhat flattened beak with a subjacent shallow notch. Posterior margin 
straight, formed chiefly by the posterior hinge-process. Dorsal aspect broadly ovate, 
once and a half as long as broad, somewhat narrowed in front. Surface smooth. 
Colour light buff, mottled with patches of a rather deeper tint. Animal unknown. 
Length 5 in. (1°9 mm.). 
Hab. Japan. Taken in the towing-net (M/r. A. Adams). 
This curious species is nearly allied to Entomoconchus scoulert, M‘Coy, but, so far as 
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