222 



S, 



116. Loxoconcha fragilis, G. O. Sars. 



(PI. ClI, fig. 3). 

 Loxoconcha fragilis, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 65. 



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

 oval subrhomboid in shape, greatest height considerably exceeding half the 

 length, dorsal margin somewhat bowed in the ocular region, but sloping other- 

 wise with a quite even and gentle curve until the tip of the .hind prominence, 

 ventral margin slightly sinuated in front and rather bowed behind, anterior 

 extremity well rounded, posterior produced above to a blunt prominence and 

 evenly rounded off below; seen dorsally, narrow oblong in outline, with the 

 greatest width in the middle and scarcely exceeding J /3 of the length, both 

 extremities evenly contracted and sharply pointed at the end. Valves very 

 thin and pellucid, with the posterior part much compressed below, surface 

 perfectly smooth and polished, without any obvious sculpture, inner duplicatures 

 remarkably broad posteriorly, marginal zone well defined and crossed by very 

 distinctly marked pore-channels. Eyes confluent. Anterior antennae very slender, 

 with all the joints of the terminal part well defined, the last about half the 

 length of the preceding one. Legs likewise comparatively slender und pro- 

 longed, last pair with the 1st joint of the terminal part about the length of 

 the other 2 combined. 



Male, as usual, smaller than female, with the shell comparatively narrower. 

 Copulative appendages rather compact and sending off below 2 or 3 irregular 

 processes, but without any distinctly defined string insides; terminal part very 

 small and not clearly defined from the basal one, projecting in front to ai 

 obtuse lobule. 



Colour of shell whitish pellucid, with a dark patch behind the ocular region 

 curving somewhat upwards at the end. 



Length of adult female 0.49 mm. 



Remarks. This is a somewhat aberrant species, differing rather con- 

 spicuously from the other known members of the present genus in the very 

 thin and fragil shell and in the wholly coalescence of the eyes. The form 

 recorded by G. W. Muller from the Gulf of Naples under the name of L. pellu- 

 cida seems to be nearly allied to the present species, though apparently distinct. 



Occurrence. Although nowhere occurring in any abundance, this form 

 has been taken in several places of the Norwegian coast, from the Christiania 

 Fjord to Lofoten, in the sublittoral region among algae. 



Distribution. British Isles. 



Fossil. Scotland. 



" 



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