^6 G. o. SARS. M.-N. Kl. 



late. Posterior maxillipeds, with the terminal part, only composed of 3 

 articulations, and armed with scattered, rather strong claw-like spines. 

 Fifth pair of legs not natatorj^, and of different structure in the two sexes, 

 somewhat resembling those in the genus Diaptomus. 



Remarks. This new genus is nearly allied to Diaptomus, though 

 differing in some points rather markedly. Thus the tail is, in the female, 

 composed of onlv 2 segments, a case very rareh' met with in the Cope- 

 poda, and the caudal rami exhibit a very different appearance in the two 

 sexes, being, in the female, highly distinguished by their large size and 

 broad lamelliform shape, whereas, in the male, they are much narrower 

 and somewhat assymetrical. Moreover, the posterior antennae, and poste- 

 rior maxillipeds, exhibit well marked differences in their structure from 

 those parts in the genus Diaptonuis. 



20. Paradiaptomus lamellatus, G. O. Sars, n. sp. 

 (PI. 7 & 8). 



Specific Characters. Bodv in female very robust, with the anterior 

 division comparatively thick and convex above, front broadly rounded. 

 Last segment of metasome produced on each side to a large triangular 

 lamella. Tail, including the caudal rami, scarcely more than half as long 

 as the anterior division of the body, ist segment considerably expanded in 

 its proximal part, 2nd segment gradually widening distally. Caudal rami 

 exceeding half the length of the tail, oval lamelliform, with the marginal 

 setae comparatively short, and bulbously dilated at the base. Body, in 

 male, more slender, with no lamellar expansions on the last seg- 

 ment of metasome. Tail rather slender, equalling in length "•^/s of the 

 anterior division, and of cylindric form. Candal rami but slightly witlening 

 distally, and haA'ing the marginal setae more elongated, the outer one of 

 the right ramus much stronger than that of the left one. Anterior antennae 

 of female scarceh' exceeding in length the anterior division of the body, 

 the right one, in the male, very distinctly geniculate. Last pair of legs, in 

 female, with the inner ramus narrow cylindric, biarticulate, and terminating 

 with 2 slender spines, outer ramus much larger, 3-articulate, 2nd joint 

 produced, inside, to a strong denticulated claw, and having, outside, a spine, 

 last joint well defined, clawlike, with a small seta inside. Those, in male, 

 very unequall}^ developed, right leg much the larger, and terminating in 

 a long and slender claw, left leg with 3 strong spines on the proximal 

 joint, the distal joint being very small, unarmed and incurved, inner ramus 

 in both legs rudimentary, conical, though somewhat larger on the right one. 



