62 



Messrs. Brady and Robertson on the 



four fifths of the length. End view subtriangular, with broad 

 truncate apex, concave sides, and almost straight base. Sur- 

 face of the shell perfectly smooth, or marked with a very few 

 distant puncta, the posterior portion behind the alae more or 

 less rugose ; lateral alte very prominent, produced to a 

 rectangular point. Animal unknown. Length -^ inch. 



Hah. Rothesay, Frith of Clyde. 



This species approaches very nearly one which we have 

 been accustomed to refer to C. vesjpevtilio^ (Reuss), but differs 

 in having a less arcuate dorsal margin, in the absence of 

 spines at the alar angles, and in the less distinctly papillose 

 or punctate shell : the corrugations of the posterior extremity 

 we have not noticed in C, vespertilio. 



Cytheropteron angulatum^ n. sp. PL II. figs. 7, 8. 



Carapace, as seen from the side, flexuous, subrhomboidal ; 

 greatest height in the middle, and equal to nearly two thirds 

 of the length : anterior extremity rounded ; posterior obliquely 

 subtruncate, narrowed, and forming an obscurely vipturned 

 beak : superior margin boldly arched, somewhat flattened in 

 the middle ; inferior nearly straight, curving upwards towards 

 the hinder extremity. Seen from above, subpentagonal, boat- 

 shaped, widest in front of the middle, acuminate in front, 

 broadly and rectangularly truncate behind ; from the widest 

 point the sides converge suddenly and almost rectilinearly 

 forwards ; behind they are markedly sinuous and less abruptly 

 convergent ; greatest width a little less than the height. The 

 surface of the shell is exceedingly rugged, the lateral alse not 

 very much produced, but having, some little distance within 

 and parallel to the margin, a strongly marked longitudinal 

 ridge, from which several irregularly flexuous ribs stretch 

 transversely across the valves, coalescing here and there into 

 large rounded eminences, and having in their interspaces nu- 

 merous irregularly angulated depressions. Length -^-L- inch. 



Hab. Roseneath, Frith of Clyde. 



This very remarkable and distinct species occurs also, in 

 the fossil state, in some of the glacial clays of the Clyde 

 district. 



7. Spitzbergen. 



Cythere laticarina, Brady. 

 — — emarginata, G. O. Sars. 



tuberculata, G. O. Sais. 



globulifera, Brady. 



Cjiihere concinna, Jones. 



mirabilis, Brady. 



diinelmensis (JVonnan). 



Cytlaeridea papillosa, Bosquet. 



* See Brady, " On Ostracoda from the Arctic Seas," Apn. & Mag. Nat. 

 Hist. July 1868. 



