of the North Atlantic and of North-Western Europe. 725 



Prionocypris serrata (Norman). 

 1889. Herpetocypris serrata, . . Beady & Noeman, '' Mon. Podocopa," p. 87. 



Genus Cypeidopsis, G. S. Brady, 1867. 



Cypridopsis, as described by Brady ("Intellectual Observer," 1867, p. 117), 

 was founded on the character of the caudal rami being " quite rudimentary, 

 consisting of two slender, setiform processes, springing from a common base." 

 Three species were included in it, C. vidua, aeuleata, and villosa. The generic 

 characters do not apply to the first, which must be removed from the genus. 



The species described which should be retained in the genus are : — 



1. Cypridopsis aeuleata (0. G. Costa). 



G. 0. Sars thinks that the Cypris aeuleata of Lilljeborg is the same species as 

 that which was described many years before by 0. G. Costa under the same 

 name (jRa!z<«a del Regno di Napoli Crostaeei Cypris, p. 11, PI. in., fig. 5). It may 

 be so, for Costa's description and figure agree closely with the northern form. 



2. C3rpridopsis villosa (Jurine). 



3. Cypridopsis Newtoni, Brady & Robertson. 



4. Cypridopsis variegata, Brady & Norman. 



Genus Pionocypeis,* nov. nom. 

 = Csrpridopsis, G. 0. Sars, 1889 {nee Brady). 



Sars' characters of the genus are as follows : — 



Shell very tumid, more or less globular in form ; dorsal margin boldly arched, 

 ventral nearly straight. Valves subequal, rather thin, hairy, inner duplicatures 

 narrow. Eye usually broad, transverse. Upper antennae (= antennules) compara- 

 tively short, but having very long natatory setae ; lower antennae rather powerful, 

 with greatly elongated apical claws, and the natatory setae reaching beyond their 

 tips. Labrum very large and vaulted. First pair of maxillae with paljjs and 

 masticatory lobes narrow and elongate ; second pair without any branchial 

 lamella. Legs about as in Cypris. Caudal rami extremely small and narrow, but 

 of quite normal structure, claws slender and setiform, three on each ramus, besides 

 a very small apical bristle. Propagation exclusively parthenogenetical. 



* ■n-Ltiiv, fat, plump. 



TEANS. BOY. DUB. SOC, N.S. VOL. T., PART XII. 5 I 



