204 



Occurrence.- Only very few specimen of this form have as yet come 

 under my notice, all of the female sex. They were taken, many years ago, 

 in the upper part of the Christiania Fjord in a depth of a few fathoms. Some 

 empty shells were moreover found by my late father in shell-sand from 0xfjord, 

 west Finmark. 



Distribution. British Isles, Arctic Sea. 



Fossil. Norway, Scotland. 



101. Cytherura sella, G. O. Sars. 



(PI. XCV, fig. 1). 

 Cytherura sella, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 73. 



Syn: Cvtherura cuneata, Brady. 

 flavescens, Brady. 



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

 oval subquadrangular in shape, scarcely higher in front than behind, greatest 

 height about equal to half the length, dorsal margin quite straight in the 

 middle joming the hind edge by an even curve, but more abruptly bent in 

 front, with indication to an angle in the ocular region, ventral margin gently 

 sinuated in the middle and joining the hind edge by a bold curve, anterior 

 extremity obtusely rounded, posterior exerted to a well defined and rather 

 narrow protuberance located distinctly above the longitudinal axis of the shell; 

 seen dorsally, narrow oblong or lanceolate in outline, with the greatest with 

 behind the middle and about equalling 2 /s of the length, anterior extremity 

 gradually tapered, posterior more abruptly contracted. Surface of valves evenly 

 convex and marked with faint longitudinal stripes connected by fine transverse 

 lines, so as to form a somewhat reticulate pattern; inner duplicatures ven 

 broad, considerably reducing the extent of the central area of the valves, which 

 is deeply emarginated behind and angularly bent in front. Anterior antennae 

 with the terminal joint only slightly shorter than the preceding joint. Posterior 

 antennas with the dividing suture of the penultimate joint located a little above 

 the middle. Legs of 1st pair with 2 setae on the infero-posteal corner of the 

 basal joint, apical claw of this and the 2nd pair almost straight. Last pair of 

 legs with the 1st joint of the terminal part much longer than the other 2 com- 

 bined, apical claw much prolonged and abruptly incurved. 



Male of smaller size than female, and having the shell, seen laterally, 

 comparatively narrower, with the corsal margin somewhat concaved; posterior 

 part of the shell considerably swollen. Copulative appendages large, with the 



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