221 



115. Loxoconcha tamarindus (Jones). 



(PI. CII, fig. 2). 



Cythere tamarindus, Jones, Tertiary Entomostraca, p. 49, PI. Ill, figs 4, a b. 

 Syn: Cythere loevata, Norman. 

 ,, Loxoconcha longipes, G. O Sars. 



Specific Characters. Female. Shell somewhat compressed, seen laterally, 

 obliquely oval in shape, greatest height only slightly exceeding half the length, 

 dorsal margin nearly straight, somewhat bent in front and slightly angular 

 behind, ventral margin a little sinuated in front and evenly bowed behind, 

 anterior extremity obliquely rounded, posterior slightly prominent above the 

 middle; seen dorsally, narrow ovate in outline, with the greatest width behind 

 the middle and about equal to 2 /5 of the length, anterior extremity gradually 

 tapered to a sharp point, posterior likewise pointed, but more abruptly con- 

 tracted at the end. Valves rather thin, with the surface quite smooth, being 

 only marked with scattered small knobs. Anterior antennae resembling in 

 structure those in L. granulata, though the mutual length of the joints of the 

 terminal part is somewhat different, the last joint being considerably longer 

 than the preceding one, which does not attains the length of the first 2 joints 

 combined. Posterior antennae almost exactly as in the said species. Legs 

 rather prolonged, though scarcely as narrow as in that species. 



Male resembling the female in its general appearance, but of somewhat 

 smaller size and having the shell comparatively narrower. Copulative append- 

 ages with the basal part oval in shape, and exhibiting inside a very distinct 

 freely projecting string curved in a circle and bent downwards; terminal part com- 

 paratively large and rather prominent in front, ending in a very sharp point, 

 being well defined at the base anteriorly, but behind confluent with the basal part. 



Colour of shell light reddish brown, with the marginal parts lighter. 



Lenght of adult female 0.60 mnr. 



Remarks. This form was recorded as early as the year 1856 by Jones from 

 fossil shells, and was subsequently observed in the living state by the present 

 author, who described it under the name of Loxoconcha longipes. It is easily 

 recognised from the 2 preceding species by the much narrower shape of the 

 shell, as also by its colour. 



Occurrence. I have met with this form occasionally in several places on 

 our coast, from the Christiania Fjord to Lofoten, in depths ranging from 10 

 to 30 fathoms. 



Distribution. British Isles, Iceland, Cap Breton, Mediterranean. 



Fossil. Norway, British Isles, Calabria. 



