KNOWN SPECIES OF MARINE OSTRACODA. 367 
below, the carapace is oval, compressed. Surface smooth, with scattered hairs. Lucid 
spots arranged in an obliquely transverse row near the centre of the carapace. 
Length 3 in. (1:05 mm.). 
Hab. Australia, 17 fathoms (Prof. Jukes’s soundings). 
Closely related to Cythere minna, Baird, but not much more than one-third of the 
size, and the posterior extremity is not nearly so acute. The greatest height is about 
the middle, whereas C. minna is highest near the front. 
2. Cyruerweis macutata, n. sp. (Pl. LVII. fig. 12, a, 0.) 
Oblong, arcuate, compressed, nearly thrice as long as broad. Anterior extremity 
tapering to a rounded point ; posterior broader, rounded, and produced below the level 
of the ventral border. Dorsal margin arched, highest in the middle. Ventral margin 
gently incurved, with a median convexity. Surface smooth, white, marked with a 
large, oval, pellucid central patch, on which are several (generally three) cloudings of 
opaque white. 
Length 3, in. (1:16 mm.). 
Hab. Australia, West Indies, Turk’s Island. 
3. CyTHERIDEIs GraciLis, Reuss. (Pl. LVIII. fig. 1, a—d.) 
Cytherina gracilis, Reuss (1850), Haidinger’s Abhand. Band iii. p. 52, t. 11. f. 3. 
? Bairdia lithodomoides, Bosquet, Entom. Fossil. des Ter. Tertiair. p. 36, pl. 2. fig. 3. 
Carapace elongate, subarcuate, convex, about twice and a half as long as broad. 
Dorsal margin arched; ventral deeply sinuate at anterior. third. Anterior border 
compressed ; posterior broad, obliquely rounded. Dorsal aspect compressed, ovate. 
The shell is smooth, transparent, mostly of a yellow tint, and, in some specimens, 
marked on its anterior portion with several concentric undulations or faint ridges, 
which run nearly parallel with the margins of the valves. 
Length 3g in. (‘73 mm.). 
Hab. Levant (sponge-sand). : 
Very nearly allied to Cythere angustata, Von Minster, but altogether smaller and more 
fragile, and possibly only a variety of it. I have ascribed my specimens to C. gracilis 
merely from comparison with the figures of that species, having seen no authentic 
specimens of it; and I am not able to detect any valid distinction between it and 
C. angustata. 
In outline this agrees very closely with Reuss’s figure, and in surface-marking 
with Bosquet’s; so that it would seem probable that these may properly be re- 
garded as varieties of one and the same species. Yet, in most of my specimens, the 
concentric ruge are absent, and in some the sinuation of the ventral margin is scarcely 
perceptible. 
