396 DR. G. 8S. BRADY ON THE OSTRACODA 
being in the shape, regularity, and degree of development of the spines. ‘The spines 
vary in shape from that of evenly rounded blunt teeth of regular size to that of long 
and slender, or flat, squamous processes. In the best-developed recent specimens 
(those especially from the North Sea) the first-named condition occurs, and the rows of 
spines are arranged with much regularity ; in others (as for instance in many specimens 
from the Mediterranean and in most of the fossil examples) the spines are less regular 
in arrangement, and tend either to become few, long and slender, or flattened and squa- 
miform: but there are all shades of gradation between these extreme types. The figures 
in Pl. LXVII. are taken with great accuracy from a fine fossil specimen illustrating an 
intermediate condition, but with rather a marked tendency to a squamous form of the 
spines, except on the posterior margin. 
C. jonesit occurs in all the Antwerp beds except in that of Trophon antiquum, but 
nowhere in much abundance. 
CYTUERE LIMA, Reuss. 
Cythere lima, Reuss, Zeitschrift d. deutsch. geol. Ges. 1855, p. 280, t. x. fig. 7. 
One valve, referable apparently to this species, was found in the Panopwa-menardi 
bed; but, owing to its having been lost or mislaid, I am unfortunately not able to 
describe it. 
Genus CyTHERIDEA, Bosquet. 
Valves unequal, ovate or subtriangular, highest near the front; smooth or marked 
with scattered circular papille, with impressed puncta or concentric furrows; hinge 
composed of two crenulated crests on one valve, which articulate with depressions of 
the opposite valve. Upper antenne very robust, mostly 5-jointed, spinous; lower 
4-jointed. Mandibular palp 5-jointed, and having a distinct branchial appendage. 
Right foot of the first and second pairs of feet, in the male, different from the rest, that 
of the first very strong and prehensile, of the second very feeble; the apex rudimentary 
and destitute of a terminal claw. Eyes distinct. 
CYTHERIDEA PAPILLOSA, Bosquet. 
Cytheridea papillosa, Bosquet, Entom. fossil. terr. Tertiair. France, p. 42, pl. u. fig. 5 (1852) ; 
Brady, Trans. Zool. Soc. Lond. (1865), vol. v. p. 370, pl. lvii. figs. 8a-g; Brady, Monog. 
Recent Brit. Ostrac., Trans. Linn. Soc. vol. xxvi. (1868) p. 423, pl. xxvii. figs. 1-6, pl. xl. fig. 1; 
Brady, Crosskey, and Robertson, Monog. Post-tert. Entom. Scotland, p. 176, pl. vi. figs. 12-15 
(1874). 
Cythere bradii, Norman, Nat.-Hist. Trans. Northumberland and Durham, vol. i. p. 15, pl. v. figs. 5-8 
(1865). 
Cyprideis bairdii, Sars, Oversigt af Norges Marine Ostracoder, p. 52 (1865). 
Var. levis. (Plate LXII. figs. 1 a—1 d.) 
Carapace, as seen from the side, subovate, highest a little in front of the middle, 
height equal to half the length; anterior extremity broadly and evenly, posterior only 
