180 



Posterior antennae with the terminal joint rather small, apical claw moderately 

 slender, lateral spine scarcely exceeding in length V 3 f the claw. 



Male of smaller size than female, and hawing the shell rather narrower, 

 with the dorsal margin slightly concaved. Copulative appendages with the 

 basal part oblong quadrangular in shape and narrowly truncated above, terminal 

 part produced in front to a narrow lappet obtuse at the tip. 



Colour of shell light yellowish brown. 



Length of adult female 0.75 mm., of male 0.64 mm. 



Remarks. This form was described as early as the year 1865 by the 

 present author; but as the specific name at that time proposed had been 

 preoccupied by Speyer for another Cytherid, it was subsequently chanced by 

 Brady as above. It is an easily recognisable form, distinguished at once from 

 most, other Cytherids by the peculiar shape of the shell. 



Occurrence. The present Cytherid is of rather rare occurrence. I have 

 only met with it quite occasionally in some places on the south coast of Nor- 

 way (Langesund, Risor), at moderate depths. Norman has recorded it also 

 from the Hardanger Fjord, at Lervik. 



Distribution. British Isles. 



Fossil. Norway, Scotland. 



Gen, 39. Kyphocythere, G. O. Sars, n. 



Generic Characters. Shell short, ventricose, angular, with the surface 

 partly rugose and provided with scattered nodiform protuberances. Valves 

 subequal, rather thin and fragile, faintly areolate, and everywhere very finely 

 punctate. Hinge with the closing teeth well developed. Eyes wholly abse 

 Antennae slender and attenuated, the anterior ones with the terminal pi 

 3-articulate, last joint much produced; the posterior ones with 3 slender api< 

 claws, flagellum well developed in both sexes. Mandibular palp comparative 

 narrow, with 2 plumose setae on the vibratory plate. Maxillae with the mas 

 catory lobes short and stout, palp not very slender, proximal seta of the vibrate 

 plate remarkably thickened at the base and clothed at this place with loi 

 deflexed cilia. Legs rather slender, with only a single seta of the anteri 

 border of the basal part. Caudal lamellae small, bisetose. Copulative app( 

 dages of male with the basal part of moderate size, terminal part narrowl 

 produced in front. 



Remarks. This is another new genus, which I have found it necess< 

 to establish, in order to include an anomalous species, hitherto referred to 



