22 G. 0. SARS. [SEC. ARC. EXP. FRAM 
of the 8 succeeding segments rounded and sub-contiguous; penultimate 
segment deeply emarginated behind. Last pedigerous segment very 
small. Urosome much narrower than the anterior division and scarcely 
attaining half its length, genital segment, as usual, much the largest; 
last segment very short. Caudal rami likewise short, broader than they 
are long. and transversely truncated at the end; apical sete unusually 
short and less unequal than in the other species, the inner medial seta 
but little longer than the outer, and scarcely exceeding the urosome in 
length, being remarkably dilated for the greater part of its length; inner- 
most seta longer than the outermost, both very thin. Anterior antenne 
comparatively short, with the 2nd joint much the largest, the 2 suc- 
ceeding joints gradually smaller, terminal part about twice the length of 
the preceding joint. Posterior antenne rather small, but otherwise of 
normal structure. Mandibular palp with the inner ramus shorter and 
stouter than the outer. Anterior maxillipeds with the terminal claw 
very strong and abruptly bent at the tip, appendicular lobe extremely 
small with only a single minute bristle at the tip. Posterior maxillipeds 
comparatively more powerful than in the other species. ist pair of 
legs exhibiting the structure characteristic of the genus, outer ramus 
exceeding half the length of the inner, and having the penicillate spines 
comparatively thin, inner ramus with the 1st joint rather dilated, 2nd 
joint not much narrowed and scarcely longer than the 1st, last joint 
very small, with 2 unequal claws at the tip, the inner one much the 
larger and distinctly penicillate. Natatory legs very fully developed, 
with the rami, especially those of the anterior pairs, rather broad and 
subequal in length; those of 4th pair, however, rather more slender. Last 
pair of legs not much produced, distal joint lamellar, oblong oval in 
form, and provided at the end with 4 comparatively short sete, inner 
expansion of proximal joint short, triangular, and tipped with 2 unequal 
sete. Ovisac oblong in form, and extending considerably beyond the 
tip of the caudal rami. . 
Male, as usual, much smaller and more slender than female, and 
having the anterior antenne slightly transformed, subprehensile. Last 
pair of legs very small, with the inner expansion of the proximal joint 
quite obsolete. Genital lobes each with a strong spine and two small 
hair-like bristles. 
Length of adult female about 1 mm. 
Remarks. — This is a very distinct and easily recognisable species, 
being especially distinguished by the greatly inflated anterior division of 
the body and the unusually short caudal sete. 
