20 G. O. SARS. M.-N. Kl. 



of the valves are likewise gently curved, and join both the anterior and 

 posterior edges by a strong curve. The hind edges are about half as 

 long as the ventral ones, and obliquely descending, with a slight l)ulging 

 in the middle. They join the dorsal margin at an obtuse angle, whereas 

 the rather prominent infero-posteal corners appear obtusely rounded, and 

 quite unarmed. The head is, as in the other species of the genus, remark- 

 ably erect, and quite immobile. Seen laterally, it tapers to a somewhat 

 procumbent acute rostral projection, which, however, in a ventral or dorsal 

 view of the animal, appears more blunted. The fornix is rather promi- 

 nent and, on each side, joins the carapace at a very acute angle, being 

 accordingly defined from the anterior edges of the valves by a narrow 

 incision. 



The surface of the shell is sculptured with rather distinct longitudinal 

 striae, about 25 on each side. These striae are, especialh% very conspi- 

 cuous in the posterior part of the carapace, becoming, anteriorly, more 

 irregular and flexuous, as w^ell as parth^ anastomosing with each other, thus 

 forming an irregular reticulation. On the head the striæ' are scarcely 

 visible at all, though perhaps some of them are continued for some distance 

 on its dorsal part. The inferior edges of the valves are, throughout, fringed 

 with very delicate, and rather long brisdes, which are also partly con- 

 tinued on the anterior edges, but do not extend to the infero-posteal 

 corners. 



The eye is not very large, and has the crystalline bodies rather in- 

 distinct. The ocellus is about same size as the eye, and occurs much 

 nearer to it than to the tip of the rostrum. It exhibits, in the lateral 

 view of the animal, a triangular form, being drawn out above to an acute 

 corner. 



The antennulae do not extend to the tip of the rostrum, and exhibit 

 a rather narrow^, subfusifofm shape. They are tipped by the usual fascicle 

 of olfactory papillae, and have, moreover, each anteriorly, at some distance 

 from the tip, a delicate sensory bristle. 



The antennae, oral parts and legs agree exactly with those parts as 

 described b}^ the author in the Australian species. 



The tail (fig 2), on the other hand, differs conspicuously, in being 

 comparatively broader and more expanded, with the posterior or dorsal 

 edge forming quite an even curve until the base of the terminal claws, 

 no angular projection or sinus occuring distally, as in the Australian spe- 

 cies. The edge itself is finely ciliated in its distal half, whereas, laterally, 

 a double scries of very slender, and strongly recurved, spiniform denticles 

 occurs, 10 to 12 in each row, those in the lower row being the longer. In some 



