17 



A rather considerable number of species referable to this genus have 

 been recorded in recent times from different parts of the Oceans. Most of these 

 are so closely related, that their distinction is connected with no small difficulty; 

 but there are also a few forms, which exhibit more conspicuous differences, 

 and which on this cause have been removed as types of nearly allied genera, 

 though the systematic rank of subgenera perhaps would be more appropriate. 

 Two closely allied species, unquestionably referable to the present genus, are 

 represented in the Fauna of Norway. 



5. Asterope marias (Baird). 



(PI. IX, PI. X fig. 1.) 



Cypridina marice, Baird, Proc. Zool. Soc. London, part XVIII, p. 257, PI. XVII, figs. 57. 

 Syn: Cypridina oblonga, Grube 



Cylindroleberis mariae, Brady 

 Asterope norvegica, G. O. Sars 



oblonga, G. O. Sars 

 Cylindroleberis oblonga, G. W. Miiller 



Specific Characters. Female. Shell very narrow, almost cylindrical in 

 shape, with the greatest height scarcely attaining half the length, dorsal and 

 ventral margins only very slightly curved, both extremities obtusely rounded 

 and nearly equal; -- seen dorsally, narrow oblong in outline, with the greatest 

 width about equalling 2 /5 of the length. Frontal incisure of valves rather deep 

 and narrow, occurring nearly in the middle of the anterior extremity; rostral 

 part moderately broad and terminating below in a beak- like point. Surface 

 of shell quite smooth and polished, without any obvious clothing of hairs. 

 Eyes well developed, and easily observable in the living animal, though not 

 of very large size. Inner ramus of posterior antennae very small, 3-articulate, 

 with only a single slender seta issuing from the tip. Last pair of limbs pro- 

 vided with only 12 cleaning spines. Caudal lamellae with about 10 claws, the 

 proximal ones very small, the others rapidly increasing in size distally. 



Male very unlike the female in its outward appearance, and also of some- 

 what larger size. Shell, seen laterally, of a somewhat irregular oblong shape, 

 being considerably higher in front than behind, with the dorsal margin slightly 

 gibbous in front of the middle and the posterior extremity narrowly truncated; 

 seen dorsally, much wider in front than behind. Frontal incisure of valves 

 rather shallower than in female, and the rostral part more obtuse. Valves thin 

 and pellucid, each clothed behind with a number of well-marked hairs, arranged 

 in the manner as to form a wreath arround the posterior end of the shell. 

 Eyes rather larger than in female and very conspicuous in the living animal. 



3 Ci'ustasea. 



