82 G- O. Sara. 



rather slight, lower rounded off and unarmed. Head short 

 and broad, clypeiform, the edges of the fornix forming a 

 continuous semicircular curve, without any trace of a rostral 

 projection. Surface of shell quite smooth, with only a few 

 slight punctures arranged in concentric rows near the edges 

 of the valves, anterior part of lower edges very finely ciliated, 

 middle part with a series of rather strong, almost spiniform 

 setæ issuing from somewhat within the margin. Eye of 

 moderate size; ocellus smaller than the eye, and occurring 

 about midway between it and the terminal edge of the head. 

 Antennulæ fusiform, scarcely projecting beyond the frontal 

 edge. Antennæ rather short. Lip-plate of moderate size, 

 with the lower edge slightly bulging in the middle. Ungui- 

 form spine of 1st pair of legs with 5 strong denticles, one 

 of which is at some distance from the others, apical part 

 finely spinulose. Caudal part very slender and mobile, some- 

 what flexuous, dorsal edge forming an obtusely rounded pro- 

 tuberance immediately below the anal sinus, and above it a 

 very slight angle, its distal part being somewhat concaved, 

 lower corner narrowly exserted and defined in front by a 

 deep incision, marginal denticles rather strong, and somewhat 

 increasing in size distally, about 20 in each row, 3 of them 

 occupying the lower corner; caudal claws rather elongated 

 and denticulated in their proximal half, basal denticle larger 

 than the others. Male much smaller than female, with 

 the head more erect, and the anterior part of the valves 

 more obliquely cut off. First pair of legs with a strong 

 procurved claw. Caudal part of a similar appearance to 

 that in female, except that the ventral edge forms a distinct 

 ledge io the middle for the opening of the spermatic ducts. 

 Colour of female yellowish brown or corneous. Length 

 of adult female reaching 1 mm.; that of male 0.72 mm. 



