104 



65. Thalestris longimana, Glaus. 



(PI. LIX & LX). 

 Tlialestris longimana, Claus, Die freilebenden Copepoden, p. 130, PI. XVIII, fi^s. 1 11. 



Specific, Characters. Female. Body very robust, with the back more or 

 less curved, and the segments of the anterior division sub-imbricate dorsally. 

 Cephalic segment of very large size, and conspicuously compressed in its an- 

 terior part, the epimeral parts being very deep and arcuate. Rostral projection 

 short and blunt at the tip. Urosome scarcely exceeding half the length of the 

 anterior division, and having the segments very sharply defined; genital segment 

 large and broad, seen dorsally, quadrangular in form, with the lateral parts lamel- 

 larly expanded ; last segment very small, often almost wholly concealed by the 

 preceding segment. Caudal rami comparatively short, not much longer than they 

 are broad, and transversely truncated at the tip, each with a short seta fit about 

 the middle of the outer edge, innermost but one of the apical setse much coarser 

 than the others, and about equal in length to the urosome. Eye large and very 

 conspicuous in living specimens. Anterior antennse scarcely exceeding half the 

 length of the cephalic segment, 2nd joint much the largest, about equal in length 

 to the 2 succeeding joints combined, terminal part of about the same length. 

 Anterior maxillipeds less compact than in the other species, with the claw of the 

 outermost lateral lobe smaller, terminal part distinctly developed, narrow cylin- 

 drical and biarticulate. Posterior maxillipeds exceedingly large and powerful, with 

 the hand considerably dilated, and forming a prominent angular projection below, 

 defining the palm in front, the latter deeply concaved in the middle, with the edge 

 densely spinulose throughout; terminal claw very strong and provided at the base 

 inside with a slender spine. First pair of legs with both rami of equal length, 

 the outer one somewhat narrower than the inner, and angularly bent near the 

 base, each ramus armed at the tip with 2 unequal claws finely denticulate along 

 the concave edge, and accompanied inside by a small, hair-like bristle; terminal 

 joint of outer ramus, moreover, exhibiting on the outer edge 2 minute spinules. 

 Last pair of legs exceedingly large, extending beyond the limits of the genital 

 segment; distal joint oblong oval in form, and evenly rounded at the tip; inner 

 expansion of proximal joint extending as far as the distal one, and somewhat 

 narrowed in its outer part; marginal seta? of both joints comparatively short 

 and simple. 



Male somewhat smaller than female, and easily recognised by the more 

 strongly built and geniculate anterior antennse and the distinctly 5-articulate uro- 

 some. Inner ramus of 2nd pair of legs transformed in the usual manner. Last 



