232 



126. Cytheropteron nodosum, Brady. 



(PI. CVI, fig. 3). 

 Cytheropteron nodosum, Brady, Mon. Brit. Ostracoda, p. 448, PI. XXXIV, figs. 3134. 



Specific Characters. Female. Shell comparatively more tumid than in 

 the preceding species, seen laterally, suboval in shape, greatest height in the 

 middle and about equal to 3 /s oi the length, dorsal margin quite evenly arched 

 throughout, ventral slightly sinuated in front of the middle, anterior extremity 

 obliquely rounded, posterior bluntly produced at the end; seen dorsally, 

 broadly ovate in outline, with the greatest width somewhat behind the middle 

 and rather exceeding 3 /5 of the length, side-edges evenly curved, both extre- 

 mities pointed and nearly equal. Valves rather thin, semipellucid, each exhibiting 

 dorsally 2 rounded nodiform protuberances, the one at some distance from the 

 anterior extremity, the other quite posteriorly; alaeform expansions rather slight 

 and quite evenly rounded off; surface of valves faintly punctate. Antennae 

 almost exactly as in the preceding species. Legs however comparatively more 

 slender^ last pair with the 1st joint of the terminal part exceeding somewhat 

 in length the other 2 combined. 



Colour of shell whitish, semipellucid. 



Length of adult female 0.58 mm. 



Male unknown. 



Remarks. This species is closely allied to the preceding one, and may 

 indeed, at the first sight, easily be confounded with it. On a closer exami- 

 nation it is however found to differs somewhat in the shape of the shell, and 

 more particularly in the presence of the characteristic nodiform protuberances 

 on the dorsal face of the valves, to which the name of the species alludes. 



Occurrence. Of this form likewise only a single female specimen has as 

 yet come under my notice. It was found in the same locality as the preceding 

 species. Norman has taken it also in 2 localities of our western coast. 



Distribution British Isles, Fosse de Cap Breton, Bay of Biscay, Gulf of 

 St. Lawrence. 



Fossil. British Isles, Canada. 



Subfam. 6. Bythocytherinae. 



Remarks. The type of this subfamily is the genus Bythocythere G. O. 

 Sars, with which the somewhat anomalous genus Pseudocythere G. O. Sars 

 apparently ought to be associated. Moreover I have felt justified to consider 



