120 A Synopsis of the Recent British Ostracoda. 



living specimens belonging to the typical form of Bairdia. I 

 have myself found, however, that the animal (and also the 

 shell) of B. injiata, which certainly belongs to McCoy's genus, 

 differs in some important respects from M. Minna ; it therefore 

 becomes necessary to propose another generic name for this 

 species. 



Family — C ythekim: . 



Cytheee, Miiller. — Upper antennae robust, five or six- 

 jointed, armed on the anterior margin with three long curved 

 spines, mostly one on the third and two on the fourth joint ; 

 lower four-jointed ; mandibular palp three or four-jointed, bear- 

 ing in place of branchial plate, a tuft of from two to five setae. 

 Eyes, one or two. Valves unequal, mostly thick and strong ; 

 surface variously ornamented with simple papillae, tubercles, fine 

 impressed punctations, or even with prominent ridges and spines 

 or deep fossae. Outline, as seen from the side, mostly sub- 

 reniform or quadrangular. Hinge joint formed by interlocking 

 teeth, two on the right and one or two on the left valve, with 

 sometimes an intervening bar and furrow. Marine. 



0. lutea, Miiller ; viridis, Miiller ; pellucida, Baird ; badia, 

 Norman ; tenera, Brady ; oblonga, Brady ; rubida, Brady ; 

 albomaculata, Baird ; convewa, Baird ; cuneiformis, Brady ; 

 limicola (Norman); globulifera, Brady ; tuberculata (G. 0. Sars); 

 concinna, Jones ; angulata (G. 0. Sars) ; dubia, Brady ; 

 Finmarchica (G. 0. Sars) ; villosa (G. 0. Sars) ; Jeffreysii, 

 Brady; laticarina, Brady; marginata, Norman; quadridentata, 

 Baird; emaciata, Brady; mirabilis, M.S.; mucronata (G. 0. 

 Sars) ; Dunelmensis (Norman) ; WJiiteii (Baird) ; antiquata 

 (Baird); Jonesii (Baird); acerosa, Brady; semipunctata, Brady. 

 — The thirty-one species here included under the genus 

 Cythere are distributed by G. 0. Sars and other authors 

 between the two genera Cythere and Cythereis. Considered 

 with reference to mere shell- characters no tenable line of 

 separation can be found, but Sars supposed that he had 

 discovered, in some minute but constant differences of animal 

 structure, peculiarities which sufficed to place the generic 

 distinction on a satisfactory basis. These characters were 

 chiefly that in the restricted genus Cythere the fiagellum of 

 the lower antenna was equally long in both male and. female ; 

 the mandibular palp three-jointed, and armed with simple 

 curved setae; while in Cythereis the fiagellum of the female 

 was very much shorter than in the male, the mandibular palp 

 four-jointed and bearing three stout curved and pectinated 

 setae. These distinctions, though perhaps of no great im- 

 portance, might have been allowed to form sufficient ground 

 for the division of a large and somewhat incoherent genus, 



