374 MR. G. S. BRADY ON NEW OR IMPERFECTLY 
produced. Dorsal margin slightly arched, ventral sinuate. Dorsal profile elongate, 
oval, truncate behind ; contact margins depressed so as to form a deep elongated sulcus 
posteriorly. Surface deeply excavated into large irregularly sinuous pits. 
Length go in. (42 mm.). 
Hab. Hobson’s Bay, Australia. 
7. CyTHERE VENATA, n. sp. (Pl. LIX. fig. 8, a—c.) 
Carapace elongated, broad in front. Anterior margin rounded, feebly and distantly 
serrated. Posterior margin very narrow, sharply rounded. Dorsal margin arched, 
having a conspicuous gibbosity over the anterior hinge. Ventral margin sinuated. 
Dorsal aspect ovate, with produced extremities. Valves smooth, marked with anasto- 
mosing ridges, the principal of which are thus distributed :—three rising beneath the 
dorsal protuberance, and running parallel with the anterior margin until lost on the 
inferior aspect ; three longitudinal ribs rising in two loops near the posterior extremity, 
running forwards and fading out about the middle of the valve; and one rib parallel 
with the posterior and part of the ventral margin. 
Length 3 in. (5 mm.). 
Hab. Hobson’s Bay, Australia. A few specimens. 
A small species, the surface-markings of which vary considerably, its most con- 
spicuous character being a faint longitudinal venation. In some specimens the surface 
is also raised into slight eminences or undulations. 
8. CyrHErE PLICATULA, Reuss. (Pl. LX. fig. 1, a-c.) 
Cypridina plicatula, Reuss (1849), Haidinger’s Abhandl. iii. p. 44, t. 10. fig. 23. 
Cythere plicatula, Bosquet (1850), Ent. Foss. des Terr. Tertiair. de la France, p. 92, pl.4. fig. 13. 
Carapace oblong, subquadrangular. Dorsal and ventral margins nearly parallel, the 
latter slightly sinuated, the former arched and gibbous anteriorly. Anterior extremity 
rounded ; posterior nearly straight, armed with several (four) strong teeth, which project 
straight backwards. Surface pitted, marked with four distinct longitudinal ribs. 
Dorsal aspect oval-oblong. 
Length yo in. (63 mm.). 
Hab. Smyrna (shallow water). Levant (sponge-sand). 
9, CyTHERE CATENATA, n. sp. (Pl. LX. fig. 2, a-d.) 
Carapace subtriangular, once and a half as long as broad; broadest in front, and 
encircled, except on the dorsal margin, with a flattened lamina or fillet. The ventral 
and dorsal margins converge towards the posterior extremity, which is rounded and 
narrow. Anterior margin broad and well rounded. The dorsal aspect is ovate, nar- 
rowed in front. The surface of the valves is ornamented with minute tubercles arranged 
