6 G. O. Sars. 



and somewhat procumbent, dorsal margin gently curved, and 

 forming in front of the eye a well-marked rounded pro- 

 tuberance, rostrum only shghtly prominent and blunted at 

 the tip, ventral margin straight and perfectly smooth. Eye 

 of moderate size. Ocellus very small, and placed nearer to 

 the tip of the rostrum than to the eye. Antennulæ about 

 half the length of the cephalic shield, narrow cylindric, with 

 a row of 4 or 5 strong dark-colored denticles inside; those 

 in male almost twice as long, and without the lateral den- 

 ticles. Basal part of antennæ exhibiting below, at som« 

 distance from the tip, a very conspicuous, anteriorly curving, 

 dentiform projection ; rami of moderate length, the lower one 

 a little longer than the upper, with the sabre-like seta of 

 the 1st joint about equalling in length ^/4 of the body, and 

 coarsely spinulose along one edge. Tail rather large, trans- 

 versely truncated at the tip, with the hind edge nearly 

 straight and thickly covered with hairs, which at the anterior 

 and posterior corners assume the character of dark-coloured 

 spinules; terminal claws very small, finely denticulated be- 

 hind; caudal setae about the length of the tail, with the 

 distal joint quite short, and clothed with long diverging 

 cilia. Body highly pellucid, with a faint yellowish tinge, and 

 generally exhibiting a small patch of a brownish pig- 

 ment on each valve somewhat in front of the middle; ephip- 

 piura, when fully developed, very dark, almost black. Length 

 of adult female amounting to 1.50 mm, that of male scarcely 

 exceeding 0.50 mm. 



Remarks. — As only a single species is as yet known, 

 it appears rather difficult to decide with any exactness, 

 which characters should be regarded as merely specific in 

 value. I have, however, tried in the above diagnosis to 

 bring together a number of characters, by which I think that 



