_174 



species, differing conspicuously in the shape and sculpturing of the shell, as 

 also in the structure of the copulative appendages of the male. 



Occurrence. I have only had an opportunity of examining very few 

 specimens of this form, taken, several years ago, in the laminarian region at Riser. 

 Norman has recorded it also from Drobak and from Lervik, Hardanger Fjord. 



Distribution. British Isles, Holland, Mediterranean. 



Fossil. Scottland. 



78. Leptocythere castanea, G. O. Sars. 



(PI. LXXX, fig. 1.) 

 Cythere castanea, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 32. 



Syn: Cythere propinqva, G. O. Sars. 

 , pellucida, Brady & Norman (non Baird). 



Specific Characters. Female. Shell, seen laterally, oval quadrangular in 

 shape, a little higher in front than behind, greatest height about equalling half 

 the length, dorsal margin only slightly arched, ventral distinctly sinuated in 

 front of the middle and gently curved behind, anterior extremity broadly rounded, 

 posterior obtusely truncated, with the upper corner well marked, lower obsolete; 

 seen dorsally, oblong ovate in outline, greatest width behind the middle and 

 exceeding somewhat V 3 f the lenght, anterior extremity more pointed than the 

 posterior. Valves of rather firm consistency and very little pellucid, the surfa( 

 being marked with closely set very sharply defined rounded pits, extremitif 

 clothed with fine hairs. Anterior antennae robust, resembling in shape thos 

 in L. macallana; last joint however more produced, exceeding considerably tl 

 preceding one in length. 



Male. Shell narrower and more compressed than in female, more tapered 

 behind, with the upper-posteal corner rather projecting. Copulative appendage 

 with both lappets of the terminal part greatly produced and exerted in vei 

 slender sharp points. 



Colour of shell dark reddish brown, limbs bright yellow. 



Length of adult female 0.69 mm., of male about the same. 



Remarks. This species, though nearly allied to the 2 preceding ones, 

 easily recognised by the comparatively shorter and stouter shape of the shel 

 and by the very strongly marked pittings of its surface, as also by the much 

 darker colour. As mentioned above, Brady and Norman wrongly identified it 

 with Cythere pellucida of Baird. Indeed, the name pellucida would be extremely 

 impropriate to the present species, which in reality is just distinguished by th( 



