249 



Cephalic segment about the length of the 4 succeeding segments combined, and 

 slightly contracted in front; rostral projection not much prominent and triangular 

 in form, tip narrowly rounded. The 3 succeeding segments with the lateral parts 

 rounded off and densely setiferous. Urosome much shorter than the anterior 

 division, all the segments, except the last, with well-marked lateral expansions 

 densely fringed with delicate bristles. Caudal rami short and thick, of rounded 

 quadrangular form, and somewhat divergent, being clothed inside with hair-like 

 spinules partly arranged in transversal rows, apical setae slender and divergent. 

 Anterior antennae of moderate length and somewhat thickened at the base, 7-arti- 

 culate, with the 3rd joint the longest. Posterior antennae rather stout, with the 

 outer ramus of normal structure. Posterior rnaxillipeds powerfully developed. 1st 

 pair of legs likewise rather strong, with the 2nd basal joint comparatively broad, 

 bulging considerably inside, outer ramus distinctly 3-articulate, and exceeding half 

 the length of the 1st joint of the inner, the latter fully as long as the basal part, 

 and ciliated on the inner edge, apical claw strong and curved at the tip. Natatory 

 legs well developed, inner ramus however comparatively short, with only 4 setse 

 on the terminal joint. Last pair of legs with the distal joint rather large and 

 oblong oval in form, carrying 5 comparatively short setae, that issuing from the 

 conically produced tip very thin, hair-like; inner expansion of proximal joint only 

 slightly produced, with 5 marginal setse, the outer 2 closely juxtaposed and smaller 

 than the others. Ovisac large, rounded oval in form. 



Male with the anterior antennae strongly hinged, last joint of proximal 

 part almost globose, terminal part armed at the base outside with a strong claw- 

 like projection. 3rd and 4th pairs of legs very conspicuously transformed, outer 

 ramus in both pairs much stronger than in female, with the spines considerably 

 thickened; inner ramus of 3rd pair only biarticulate, distal joint produced outside 

 to a short triangular projection, and carrying on the tip 2 unequal setae; inner 

 ramus of 4th pair reduced to a small nodiform joint carrying 2 thickish diverging 

 setae. Last pair of legs, as usual, much smaller than in female, distal joint 

 slightly widening towards the end and provided with 4 setae only; inner expansion 

 of proximal joint almost obsolete, though carrying 2 small setae. 



Colour light yellowish grey. 



Length of adult female 0.70 mm. 



Remarks. This form, first recorded by Boeck under the above name, may 

 be easily recognised by its broad depressed body, the sharp demarcation of the 

 segments, and the long diverging caudal setae. The transformation of the inner 

 rami of the 3rd and 4th pairs of legs in the male is rather unlike that generally 

 met with in the present genus. 



33 Crustacea. 



