

RECENT BRITISH OSTRACODA. 175 



CiTHERE EMAHGINATA (G. 0. Sars). 



Cythereis emarginata, G. O. Sars, loc. tit. p. 38. 



Scandinavian type. Distribution : Recent— Baffin's Bay, Norway, Shetland Fossil— (Uncial, Scotland, 

 ; Norway. 



Shell of the female, seen from the side, subreniform, highest near the middle ; greateri 



height much more than half the length. Anterior extremity rounded, posterior pro- 

 duced below the middle into a prominent angular lobe; superior margin boldly arched, 

 inferior sinuated in front of the middle and bending upwards behind. Seen from above, 

 the shell is compressed ovate; extremities broadly mucronate. Bight valve xtry 

 different from the left, higher and more boldly arched, sinuated in front of the eyes; 

 posterior extremity more deeply emarginate and more prominent below. Shell of Hie 

 male distinctly quadrangular ; greatest height scarcely exceeding half the length, end 

 situated near the front; superior margin only slightly armed; posterior obliquely trun- 

 cate. Surface irregularly sculptured with large angular excavations; the sculptured 

 portion of the shell terminating abruptly in a transverse ridge, a little in front of the 

 posterior extremity, and below in a sharply cut ventral rib, which is most conspicuous 

 posteriorly. Hinge-line marked on the dorsal aspect by a deep sulcus ; hinge-teeth large 

 and strong. 



Length -£$ in. 



Dredged by Mr. D. Robertson off Shetland. The only British species with whioh 

 C. emarginata can be confounded is C. angulata, which, however, is considerably smaller 

 and may mostly be distinguished also by the absence of any sharply cut transverse 

 declivity, the prominent tuberculatum of the valves, and often by a more or less radiate 

 arrangement of the surface-sculpture. C. eostata, Brady, an Arctic species, is a much 



nearer relative. 



Er 



sp. (Plate XXV. figs. 49, 50 



middle, greatest 



Carapace, seen from the side, subtriangular, highest in the middle, greatest neigm 

 equal to nearly two-thirds of the length ; anterior extremity broadly rounded, posterior 

 narrowed, obliquely rounded ; superior margin very strongly arched, sloping steepb 

 behind, inferior almost straight. Seen from above, the outline is compressed ovate, 

 widest in the middle, tapering to an acute point in front, more obtuse behind, he hmge- 

 Wne showing a well-defined sulcus behind the middle. Surface of the shell stony m 

 appearance, rudely punctate, and towards the margins showing traces of concentric 



furrows. 

 Length - 1 in 



m. Dredged off ihe Durham coast (G. S. *.), and off the Moreeambe Light-ship (>/, ft M-ft* 



This is referred to, under my description of E. deelim, as . small, roughly punctate 

 form of that species. Having only met with two specimens u. a single oh 

 hesitated to admit it as a distinct species ; but Mr. Robertson has recently sent me 11 

 specimens, completely identical with it, from the west coast am 

 "0 longer any doubt* respecting the propriety of assigning to then a sepa.ate specific 



I think ther 



name 



3 



