170 



POST-TERTIARY ENTOMOSTRACA. 



from the rest, that of the first pair very strong and prehensile ; of the second very feeble, 

 the apical portion rudimentary and destitute of a terminal claw. Eyes distinct. 



We include in this genus the species referred by Prof. T. Rupert Jones and G. O. 

 Sars to Cijprideis, as we are unable to find any sufficient character to distinguish these 

 from the typical Ci/theridea of M. Bosquet. Sars proposes to confine the generic term 

 Cytheridea to the form typified by his C. dentata ; but the animal structure of this 

 species is quite unknown, and the shell does not appear to exhibit any marked differen- 

 tiating character ; the difference seems to us to be one of degree merely. 



Certain species of Cytheridea are very abundant and widely distributed in the seas of 

 the present day, but the number of species is comparatively few. Most of the forms 

 described in this Monograph are, however, still flourishing in the British areaa. 



1. Cytheridea papillosa, Bosquet. Plate VI, figs. 12 — 15. 



1852. Cytiieiudea papillosa, Bosquet. Entora. foss. terr. tertiair. France, p. 42, 



pi. ii, fig. 5. 



1865. Cytheee BiiADii, Norman. Nat. Hist. Trans. Northumb. and Durham, vol. i, 



p. 15, pi. V, figs. 5 — 8 ; see also note, p. 28. 

 1865. Cypkideis Bairdii, G. O. Sars. Oversigt af Norges marine Ostracoder, 



p. 52. 



1865. Cytheridea papillosa, Brady. On new or imperfectly known species of 



Marine Ostracoda ; Trans. Zool. Soc, 

 vol. V, p. 3/0, pi. Iviii, figs. 8 a — g. 

 1868. — — Brady. Monog. Kec. Brit. Ostrac, Trans Lin. Soc, 



vol. xxvi, p. 423, pi. xxviii, figs. 1 — 6, 

 pi. xl, fig. 1. 



Carapace of the female, as seen from the side, subovate, highest near the middle ; 

 greatest height equal to rather more than half the length. Anterior extremity evenly, 

 posterior obliquely rounded. Superior margin well arched, forming a continuous curve 

 as far as the infero-posteal angle of the carapace, inferior margin slightly sinuated in 

 the middle, the infero-posteal angle more exserted. Outline, as seen from above, ovate, 

 widest behind the middle, greatest width equal to half the length ; end-view nearly 

 circular ; surface of the shell smooth and polished, bearing numerous scattered circular 

 tubercles or papillae, and sometimes shghtly punctate. Lucid spots large and con- 

 spicuous. 



The shell of the male is narrower and more elongated, and its dorsal margin is 

 much flattened and nearly parallel with the ventral. 

 Length, -^th of an inch. 

 This species has been already identified by one of us with M. Bosquet's Cytheridea 



