121 



only slightly exceeding half the length. Cephalic segment very large, nearly twice 

 as long as the remainder of the body, and narrowly rounded in front, with 

 no crista dorsally; rostral prominence very small. Epimeral lappets of the 2 

 succeeding segments rather broad and curved backwards; those of penultimate 

 segment extremely small and conical in form, being almost wholly concealed in 

 the dorsal view of the animal. Tail scarcely exceeding in length ] /4 of the 

 anterior division, genital segment much dilated in its anterior part. Caudal 

 rami very short, being scarcely longer than they are broad, and transversely 

 truncated at the end. " outermost seta attached close to the apex and much 

 shorter than the innermost one; inner mediate seta twice as long as the outer, 

 and attaining about half the length of the body. Anterior antennae of moderate 

 length and composed of 9 joints, the elongate 2nd joint however exhibiting at 

 the base and at the end slight traces of a subdivision; terminal joint somewhat 

 longer than the 2 preceding ones combined. Posterior antennae with the last Q 

 joints of about equal size; middle apical seta rather slender and flexuous. Siphon 

 extremely slender, extending almost to the end of the anterior division of the 

 body. Maxilla^ with the outer lobe scarcely more than half as long as the 

 inner and having the 2 apical setce rather unequal in length; apical seta of inner 

 lobe very slender. Anterior maxillipeds with the dactylus much elongated and 

 narrow, secondary spine of moderate size and attached at a short distance from 

 the apical claw. Posterior maxillipeds with the hand densely ciliated outside. 

 1st pair of legs considerably smaller than the 2 succeeding pairs, but having the 

 terminal joint of the outer ramus well developed; 2nd and 3rd pairs rather 

 strongly built, with the 2nd basal joint lamellarly produced inside; 4th pair with 

 the outer ramus smaller than that of the 2 preceding pairs, but otherwise of a 

 very similar structure, inner ramus wholly absent. Last pair of legs about as 

 in Dysponiius striatus. 



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

 somewhat more depressed. Anterior antennae composed of only 10 joints, no 

 apical joint being cut off; 8th joint somewhat dilated and exhibiting near the 

 end in front a short dentiform projection. 



Body in female of a whitish grey colour, with a faint yellow tinge. 



Length of adult female 0.90 mm., of male 0.75 mm. 



Remarks. I cannot doubt that the above-described form is identical with 

 Giesbrecht's species, though there are some few points of discrepancy. It is an 

 easily recognizable species, differing conspicuously from the other Dyspontiidw 

 in the general form of the body, especially as regards the female. 



16 Crustacea, 



