310 



nearly as long as the 4 succeeding segments combined, rostral projection trian- 

 gular, acute at the tip. Epimeral plates of the 3 succeeding segments rounded 

 off. Last pedigerous segment rather short, but scarcely narrower than the preced- 

 ing segment. Urosome a little shorter than the anterior division, genital segment 

 about the length of the 2 succeeding segments combined, and somewhat protuberant 

 below, last segment much larger than the preceding one, and having the anal 

 opercle jrather small and perfectly smooth. Caudal rami very thick at the base 

 and tapering somewhat distally, each with 2 successive bristles on the outer edge, 

 the distal one unusually long and slender, extending generally straight outwards; 

 middle apical seta of normal structure, and scarcely longer than the urosome. 

 Anterior antennae about half the length of the cephalic segment, the 3 joints of 

 the proximal part of about equal size, terminal part scarcely longer than the last 

 joint of the proximal, and having some of the setse rather strong and distinctly 

 ciliated. Posterior antennae with the distal joint a little shorter than the proximal, 

 and gradually widening towards the end; outer ramus comparatively small, 

 with the distal joint quite short. 1st pair of legs with the joints of the outer 

 ramus of nearly equal size, the last one armed with 2 spines and 2 slender genicu- 

 late setae; inner ramus fully as long as the outer, proximal joint rather broad, 

 with a slender seta inside, distal joint a little longer and much narrower, carrying 

 on the tip a strong claw-like spine and a slender seta. The 3 succeeding pairs 

 of legs with the terminal joint of the outer ramus much produced, being about 

 as long as the 2 preceding joints combined, and armed with 3 strong spines and 

 a small apical seta, inner edge of the joint in the 2nd and 3rd pairs carrying 

 a single seta near the base, in the 4th pair 2 setae, middle joint in this pair with 

 another seta inside, which is wanting in the other pairs. Inner ramus in 2nd to 4th 

 pairs very small, with a single apical spine; that of 4th pair quite rudimentary. 

 Last pair of legs forming each an obliquely transverse plate fringed with 10 

 slender setae, the outermost one attached to a knob-like prominence. 



Male, as usual, smaller than female, and having the anterior antennae 

 very strongly hinged, 6-articulate. Inner ramus of 2nd and 3rd pairs with the 

 apical spine comparatively longer than in female. Last pair of legs of somewhat 

 smaller size, but otherwise of much the same structure as in the female. 



Colour whitish grey. 



Length of adult female 0.53 mm. 



Remarks. This form may be easily recognixed by its short, stout, 

 cylindrical body, and by the thick caudal rami, with the very slender bristle 

 springing from their outer edge. 



