THALESTRIS. 122 
A. THALESTRIS HARPACTOIDES, Claus. Pl. L, fies. 9—16; 
iC Wa ole pope alee Me 
Thalestris harpactoides, Claus. Die frei lebenden Copepoden, 
p. 133, taf. xix, figs. 2—11 (1863). 
Body very slender and elongated, subsigmoid in 
outline; abdomen scarcely at all narrower than the 
cephalothorax ; each segment bordered by a more or 
less distinct belt; rostrum of moderate size, slender ; 
anterior antenna (fig. 9) 9-jointed, slender; inner 
branch of lower antenna 2-jointed. Second foot-jaw 
(fig. 12) slender; hand elongated, ovate, much like 
that of T. rufocincta, but the terminal claw is devoid of 
basal setze, and is only l-jointed. Mouth organs and 
first pair of feet also like those of rufocincta, but the 
marginal sete of inner branch longer. The fifth pair 
of feet in the female have a large, broadly triangular 
basal joint (fig. 14) with ciliated inner margin, and five 
setze of moderate length ; second joint broadly oval, 
ciliated, obliquely truncate, and dentate distally, bear- 
ine six setz, not much longer than the first joint ; 
fifth feet of the male (fig. 15) almost exactly like those 
of rufocincta. Abdominal segments (fig. 16) short 
and wide, ciliated laterally, the first two scarcely 
wider than the rest, and not produced into lateral 
angles; posterior margins of the last two segments 
finely dentate; the second segment has also two spine- 
like appendages (aa). Caudal segments about as long 
as broad, armed with a small spine on the outer angle; 
tail sete rather short, the inner one about as long as 
