386 DR. G. S. BRADY OX THE OSTRACODA 



proportions of the shell are also liable to considerable variation during the process of 

 growth. 



Cythere jurinei occurs in moderate abundance in the Pectunctihis and Panopcea- 

 menardi beds (Sables inferieurs), also in the Trophon-antiquum bed (Sables superieurs). 



Ctthere PLiCATA, Miiuster. (Plate LXV. figs. 5 «-5 d.) 



Cyfhere plicata, Munster, Jabrb. fiir Mineralogie, &c., 1830, p. 03, and Neues Jahrb. &c. 1835, 



p. 446 (fide Jones et Bosquet). 

 Cythere plicata, Romer, Neues Jahrb. fiir Min. &c. 1838, p. 518, pi. \i. fig. 26 (fide Jones et Bosquet) . 

 Cypridina laticosta, Reuss, Haidinger's Abhandl. iii. p. 87, pi. ii. fig. 13. 



Cythere plicata, Bosquet, Entom. fossU. des terr. Tertiair. de la France, &c., p. 60, tab. ii. fig. 13. 

 Cythere plicata, Jones, Tertiary Entomostraca of England, p. 32, pi. iv. fig. 16, and pi. v. figs. 8a- 



8rf (?pl.v. fig. 17). 

 Cythere plicata, Egger, Die Ostrak. der Miocan-Schichten bei Orenburg (1858), p. 24, pi. v. fig. 9 



(icones malae). 

 Cythere plicata, Speyer, Die Ostrac. der Casseler Tertiarbildungen (1863), p. 29, pi. iv. figs. 2a,6,c, rf. 



Carapace, as seen from the side, oblong, subquadrangular ; length equal to rather 

 more than twice the height. Anterior extremity wide and well rounded, posterior 

 narrowed, and armed with three or four blunt teeth ; dorsal and ventral margins nearly 

 straight in front, but converging towards the posterior extremity. Seen from above, 

 oblong-ovate, tapering gradually toward the front, and abruptly behind ; extremities 

 obtusely pointed ; greatest width near the hinder extremity, and equal to half the length. 

 End view irregularly quadrate, the lateral margins having each a large central promi- 

 nence. The valves are marked by three large, curved and rounded longitudinal ribs, 

 the central one being the most prominent : the ribs themselves are smooth ; but the 

 intermediate furrows are sculptured with large rounded pittings. The hinge-line is 

 marked by a deep depression. Length ^ inch (0-85 millim.). 



C. plicata occurs in moderate abundance in both beds of the " Sables moyens " and 

 much more rarely in the Panopcea-hedi (Sables inferieurs). It is noted by Professor 

 Rupert Jones as occurring in the middle Eocene of the Isle of Wight and Hampshire ; 

 and the same author states that " it has been found in the Miocene deposits of Dax, 

 and in the Eocene of France, Belgium, North-western Germany, Bohemia, Austria, and 

 Moravia." In some of these deposits it seems to be very abundant, and, indeed, may be 

 looked upon as one of the commonest and most widely distributed of the Tertiary 

 Ostracoda. It is, moreover, very distinct in its characters, and scarcely likely to be 

 confused with any other species, at any rate in its typical form. 



Cythere belgica, nov. sp. (Plate LXV. figs. 3 «, 3 b.) 



Carapace, seen from the side, subrhomboidal, somewhat higher in front than behind ; 

 height equal to half the length ; extremities obliquely rounded ; dorsal margin straight, 

 sloping gently from before backwards ; ventral shghtly convex. Outline, seen dorsally, 



