CYTHERE. 145 



with vaguely defined rounded impressions which, towards the extremities, sometimes tend 

 to form elongated furrows or undulations. The shell of the male is narrower, less 

 deeply sinuated below and more upturned at the posterior extremity. 

 Length s^th of an inch. 



Distribution. Becent. — Great Britain, Ireland, Holland. 



Fossil — Scotland : Kilchattan, Cumbrae, Cartsdyke, Dalmuir, West Tarbert. South 

 Wales : Cardiff New Dock basin. 



5. Cythere tenera, Brady. Plate XIII, figs. 6, 7. 



1868. Cythere tenera, Brady. Monog. recent Brit. Ostr., p. 399, pi. xxviii, 



figs. 29—32. 



Carapace, as seen from the side, oblong, sub quadrangular, of nearly equal height 

 throughout ; height equal to half the length ; anterior extremity well rounded, posterior 

 subtruncate, rounded off below, obscurely angulated above ; superior margin straight, 

 gently sloping from before backwards ; inferior sinuated in the middle. Seen from above, 

 ovate, widest about the middle, width less than the height ; shell-surface smooth, very 

 finely punctate, and ornamented also with a few distant small circular papillae ; no 

 transverse sulcus. 



Length of the Cardiff specimens y^th of an inch. Usual size y^-th of an 

 inch. 



Distrirution. Becent. — Great Britain, Ireland, Shetland, Bay of Biscay, Besika 

 Bay. 



Fossil. — Scotland : Wick, Dipple, Oban. South Wales : Cardiff New Dock basin. 



5. Cythere deflexa, nov. sp. Plate XIII, figs. 14, 15. 



Valves, as seen from the side, reniform : greatest height situated near the middle and 

 equal to scarcely half the length ; extremities well rounded ; superior margin arched, 

 almost gibbous in the middle ; inferior sinuated. Seen from above, regularly ovate. 

 Shell-surface marked with indistinct, subconcentrically arranged pittings. 

 Length s^th of an inch. 



The single valve on which this species is founded does not seem fairly referable to any 

 known form, though in general appearance it approaches somewhat C. cribrosa, from 

 which it is separated chiefly by its more flexuous outline and more arcuate dorsal 

 margin. 



Fossil. — Scotland: Jordan Hill. 



19 



