152 THE VOYAGE OF H.M.S. CHALLENGES. 



filaments attaelied to the first pair of antennae ■wliich is cliaracteristic of the males. The 

 shape of the shell, too, is usually very different in the two sexes, the male being very 

 long and slender in comparison with the female. Judging from the large number of fossil 

 species belonging to this fixmily which have been found in the Coal Measures^ and other 

 Palaeozoic formations, we must suppose that the Cypridinidse were much more abundant 

 in old times than now ; we may, perhaps, likewise infer that they were chiefly inhabitants 

 of shallow warm water, possibly of brackish and estuarine localities. Some few species 

 have been described from Cretaceous and Tertiary strata, but it would appear that the 

 group attained its greatest development in the Carboniferous era, and has been gradually 

 losing ground since that time, until it has in our days come to be almost swamped by the 

 smaller, hardier, and, doubtless, also more prolific species of the families Cypridse and 

 Cytheridse, animals evidently of much more plastic organisation, and more capable of 

 adaptation to varied conditions of environment. 



The following list comprises, so far as I know, all tlie recent species hitherto described. 

 Of these the shell only has in many cases been examined, and in many more the con- 

 tained animal, though partially described, has not been observed with suflicient accuracy 

 to allow of certain generic reference. Several of the numerous forms here noted as 

 CypridincB will, doubtless, when better known, be ranged under other genera. 



Cypridina reynaudi, M. Edwards, 1840, Hist. Nat. Crust., tom. iii. p. 409, t. xxxvi. 

 fig. 5 (Indian Ocean). 



Cyjyridina [Asterojoe '^) adamsi, Baird, 1848, Ann. and Mag. Nat. Hist,, 2d series^ 

 vol. i. pi. viii. (South Atlantic). 



Cypridina (Vj bimactdata, Nicolet, 1849. (Marshes of Chile.) 



Cypris himaculata, Nicolet, Gay, Hist. Fisio.a y politica de Cliile, t. iv. fig. 66. 



Cypridina (?) ccendea, Nicolet, 1849. (Marshes of Chile.) 

 Cypris ccerulea, Nicolet, Gay, Hist. Fisica de Cliile, t. iv. fig. 66. 



Cypridina zealandica, Baird, 1851, Proc. Zool. Soc. (Annulosa), t. xvii. figs. 11-13 

 (New Zealand). 



Cyioridina (?) gibhosa, Dana, 1853, Crustacea of United States' Exploring Expedition, 

 p. 1295, t. xci. fig. 4 (Pacific Ocean). 



Cypridina I^T) formosa, Dana, 1853, Crustacea, United States' Exploring Expedition, 

 p. 1296, t. xci. fig. 5 (Samoan Islands). 



1 See Jones and Kirkby, Entomostraca of the Carboniferous Formations (Palseontograpliical Society, 1874). 



