8 &. O. Sars. 



being continued, as usual, along the lower edge of the shell- 

 spine to its tip. The spine, moreover, exhibits 2 lateral and 

 one dorsal row of similar denticles, the dorsal row being 

 continued in front along the dorsal margin of the shell as 

 far as the cervical region. The sculpture of the shell is the 

 usual one, consisting of 2 sets of curved striæ crossing each 

 other at nearly right angles. 



The eye is of moderate size, and placed somewhat 

 within the anterior edge of the head, at its junction with 

 the ventral one. It exhibits a number of distinct crystalline 

 bodies projecting from the dark pigment. The ocellus is 

 extremely minute, punctiform, and located at some distance 

 behind the eye, at the inferior end of the cerebral ganglion. 



The antennulæ, as in D. Thomsoni, are very small, and 

 scarcely project beyond the shell of the head, except with 

 their apical bundle of olfactory papillæ. 



The antennæ are constructed in the usual manner, and 

 have the natatory setæ densely plumose. 



The tail exhibits dorsally the usual curved lappets, and 

 has the terminal part (see fig. 2) comparatively short and coni- 

 cally tapering distally, with the posterior edge perfectly 

 straight and densely hairy in its upper part. The anal den- 

 ticles are rather small and of uniform length, about 12 ou each 

 side. The terminal claws are comparatively much shorter 

 and stouter than in D. Thomsoni, and are destitute of any 

 trace of secondary denticles, though a delicate ciliation may 

 be observed along their concave edge. 



The cæcal appendages of the intestine are of moderate 

 size, and but slightly sigmoid. 



The ova in the matrix, in large specimens, are very 

 numerous and of comparatively small size. 



