22 



remaining joints combined, all the natatory setae terminating in a thin lance- 

 olate point; inner ramus with the proximal joint remarkably expanded behind 

 and produced anteriorly into 2 successive mamilliiorm processes, the lower of 

 which is tipped with 2 short bristles; distal joint in male with 2 of the apical 

 setae much elongated, and the hook constantly more strongly developed 

 on the right than on the left antenna. Anterior lip forming in front 

 large, hood-like prominence. Maxillipeds with the basal part produced anteri- 

 orly to a well-marked masticatory prominence, palp 3-articulate and rapidly 

 tapered distally, its last joint very small and armed with 3 slender anteriorly 

 curved claws of unequal length. Anterior legs slender, 5-articulate, their out 

 part being in female of a similar structure to that of the palp of the maxillipeds 

 and generally projected from the shell below; those in male conspicuously 

 transformed, being more powerfully developed and as a rule, concealed within 

 the shell, terminating in 3 subequal, densely crowded setae more or less 

 abruptly bent in their outer part, and generally projecting from the shell, 

 at its upper posterior corner. Posterior legs very small, imperfectly biarticulate, 

 and terminating in 2 slender setae, the one of which is very elongate. Caudal 

 lamellae, each armed anteriorly with a slender spine, curving downwards in 

 front of the marginal claws. The latter somewhat compressed and gradually 

 diminishing in size proximally. Copulatory appendage in male oblong in shape 

 and scarcely lobular at the end. 



Remarks. This genus was established as early as the year 1849 by 

 Dana, and was subsequently divided by the same author into the 2 genera 

 Conchoecia (proper) and Halocypris, both being comprised within the sub- 

 family Halocyprince, which together with the subfamily Cyprldinince constituted 

 his family Halocypridce. The genus may be easily distinguished from Halo- 

 cypris by the more elongated and far less tumid shell, as also by the very 

 distinct rostral prominences of the same. It comprises numerous species from 

 nearly all parts of the Oceans explored. To the Norwegian Fauna belong 3 

 well defined species, to be described in the sequel. 



7. Conchoecia elegans, G. O. Sars. 



(PI. XI & XII). 

 Conchoecia elegans, G. O. Sars, Oversigt af Norges marine Oslracoder, p. 117. 



Syn : Paraconchoecia gracilis, Glaus. 



Conchoecia quadrangularis, Aurivillius. 



Specific Characters.- -Female. Shell rather slender and elongated, seen 

 laterally, almost cuneiform in shape, being gradually narrowed from behind 



