12 A REVISION- OF THE BRITISH SPECIES OF 



from the same plane or nearly so, and the presence on the in- 

 ternal margins of the protopodite in the second, third, and fourth 

 pairs of feet, of rounded laminar projections, which have spinu- 

 lose margins. I have myself found the same variety in a collec- 

 tion from Lough Fadda, Connemara. Figures of this remarkable 

 form are given in Plate VI. 



The character which, so far as I know, distinguishes at once 

 C. Scourjieldi from all other species is the presence, on the second 

 joint of the posterior maxilliped, of a series of short marginal 

 setse. The crenulation of the posterior margin of the anterior 

 maxilliped is a less constant character, but perhaps also diag- 

 nostic when it occurs. The apical dilatations of the inner 

 branches of the swimming feet — more especially of the fourth 

 pair — is another, and perhaps more important, character, which, 

 however, is wanting in the Higham Park specimens. 



/?. Anterior antennae, Avhen reflexed, not distinctly longer than 

 the first somite. 



6. Cyclops vicinus, Uljanin (PL L, figs. 6-9). 



1875. Cyclops vicinus, Uljanin (28), p. 30, pi. X., figs. 1-7 ; 



pi. XII., figs. 7-9. 

 1878. Cyclops pulchellus, Brady (32), p. 107, pi. XVIL, 



figs. 1-3. 



Professor Gr. 0. Sars has kindly examined specimens of the 

 species ascribed by me in my Ray Society Monograph to Cyclops 

 pulchellus, Koch, and believes them to be quite distinct from the 

 form described by himself as C. pulchellus, and likewise from the 

 very nearly related C. lucidulus, Koch. He suggests that they 

 come nearer to C. strenuus, Fischer, and I have, in fact, some- 

 times found it difficult to distinguish between the two species, 

 but the shorter antennas, the comparatively small size of the 

 cephalic segment in the present species, the very marked and 

 prominently angular outlines of the following three segments, 

 and the different character of the caudal rami and setse, forbid 

 its being ascribed to C. strenuus. On the other hand, the very 

 beautiful drawings of C. vicinus given by Uljanin, in his memoir 

 on the Crustacea of Turkestan, agree most accurately with this 

 species. I therefore adopt the name proposed by that author. 



77 



