182 



renders this form easily recognisable, from any of the species described in the 

 preceding pages. 



Occurrence. Some few specimens of this Cytherid have been collected 

 many years ago, partly in the Trondhjem Fjord, partly off the Lofoten islands 

 (Odvaer), frotrTrather considerable depths ranging to 100 fathoms, muddy bottom. 



Distribution. British Isles. 



Fossil. Scotland. 





Gen. 40. Hemicythere, G. O. Sars, n. 



Generic Characters. Shell of very solid consistency, calcareous, resembling 

 somewhat in shape that of Cythere. Valves more or less unequal, with the 

 surface distincly pitted or roughly reticulate, marginal zone closely striated, edges 

 densely hairy in front. Hinge with the closing teeth well developed. Eyes 

 distinctly separated. Anterior antennae with the terminal part 3-articulate, 

 middle joint elongated, with 2 claw-like spines in front, last joint moderately 

 produced. Posterior antennae with 3 apical claws, the 2 proximal ones much 

 thinner than the distal; flagellum in male normally developed, in female much 

 shorter and somewhat thickened in the middle, with the extremity very delicate 

 and blunted at the tip. Mandibles with the cutting part very coarse, palp 

 almost straight, with the terminal joint comparatively short, vibratory plate 

 small, with only a single plumose seta accompanied outside by a rudimentary 

 hook-like spine. Maxillae with the masticatory lobes comparatively short, palp 

 of moderate size. Legs moderately strong, the 2 anterior pairs with 2 setae 

 on the anterior border of the basal part: last pair with only a single such seta. 

 Caudal lamellae small, with 2 plumose setae on the tip. Copulative appendages 

 of male with the terminal part well defined, triangular in shape. 



Remarks. This new genus is proposed to comprise a number of species 

 generally referred by recent authors to the genus Cythereis, but differing from 

 this genus, as defined by Jones, in several regards. It holds in reality 

 intermediate position between this genus and Cythere (in the restriction he 

 adopted), approaching in some respects more closely to the latter genus, 

 the Fauna of Norway 8 species, referable to this genus, are represented. 



84. Hemicythere villosa, G. O. Sars. 



(PL LXXXIV.) 

 Cythere villosa, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 42. 



Specific Characters. Female. Shell, seen laterally, subreniform in shape, 

 greatest height about in the middle and exceeding half the length, dorsal margin 



