RECENT BRITISH OSTRACODA. 



377 



3. Cypridopsis villosa (Jurine). (Plate XXIV. figs. 11-15, and Plate XXXVI. fig. 9.) 



Monoculus villosus, Jurine, Hist, des Monocles, p. 178, pi. xix. tigs. 14, 15. 

 Cypris Westwoodii, Baird, Brit. Entom. p. 156, pi. xix. fig. 9. 

 ■ ? elongata, Baird, Brit. Entom. p. 156, pi. xix. fig. 6. 



Carapace compressed, oblong, reniform ; height equal to more than half the length. 

 The dorsal margin is boldly arched, highest in the middle ; the ventral margin deeply 

 incurved along its entire length. The anterior border is broad and rounded, the posterior 

 somewhat produced, forming an obscure angle inferiorly. Outline, as seen from above, 

 compressed, oval, pointed in front and rounded behind ; about twice and a half as long 

 as broad. End view oval, rounded at the base, pointed above. Surface of the shell 

 covered with long, fine hairs. Colour light grass-green. 



Length -^q in., height 7^5- in. ^,-0 w^-. f . i ;-;. 



This is one of the less common species of freshwater Cypridae. It has been found at 

 Yetholm Loch, Hoxburghshire, by Dr. Baird ; at Sedgefield, Durham, by the Rev. A. 

 M. Norman; in moorland pools near Easedale Tarn, Westmoreland, in a pool near 

 Cotherston, Yorkshu^e, in Belsay East Lake and near Crag Lake, Northumberland, and in 

 ponds at Silksworth and Eulwell, near Sunderland, by myself ; also by Mr. D. Eobertson 

 in a pool near Banff. 



The nearest ally of this species is C. aculeata (Lillj.). C. villosa, however, is much 

 less tumid, the ventral margin much more deeply arched, the dorsal margin not rising 

 to a point, while the surface of the shell is destitute of spines, and clad with much less 

 rigid hairs than those of C. aculeata. 



Cypris elongata, Baird, appears to me to be the young form of C villosa. 



Genus 3. Pahacypuis, G. O. Sars. 



Shell smooth, compact, much higher in front than behind. Upper antennae seven- 

 jointed, wshortly setiferous ; lower stout, terminating in four strong curved claws, three 

 of which are nearly equal in length, the other considerably shorter, antepenultimate 

 joint bearing at its base a pedicellated hyaline vesicle. Mandibles terminating in five 

 or six rather long teeth, and bearing a four -jointed palp, from the basal joints of which 

 springs a narrow branchial appendage. ".The external lobe or palp of the first pair of 

 jaws linear, scarcely broader than the rest. Second pair of jaws provided with a bran- 

 chial appendage ; the palp elongated, conical and inarticulate " *. Last pair of feet 

 similar to the first in form and size ; both pairs five-jointed, and terminating in a long 



* I have had no opportunity of verifying these particulars, most of my British specimens having come into my 

 hands either as mere empty shells, or containing, at best, mutilated animals. The portion of the geueric definition 

 contained within inverted commas is, therefore, quoted from G. O. Sars ; and I may here, once for all, state that wliere 

 similar quotations are made in subsequent parts of this memoir they are derived from the same source, and are inserted 

 for the same reason. The drawings, however, it may be proper to say, have been in all cases done by myself, direct 

 from nature ; and through the kindness of Herr G. O. Sars in furnishing me with Norwegian specimens, I have, in some 

 cases, been able to give illustrations of the anatomy of species which could not have been derived from British examples. 

 These remarks apply almost exclusively to the very rarest species ; but, when practicable, I have always preferred to 

 draw from native specimens, and have never used foreign ones when there could be the least doubt as to their 

 identity. 



VOL. XXVI. 3 F 



