110 



THE VOYAGE OF H.M.S. CHALLENGEK. 



with eiutor plates the larger, aud exhibiting exteriorly a small tooth somewhat remote 

 from the apex. Length reaching 48 mm. 



Remarks. — Among the drawings executed during the expedition by the late Dr. v. 

 Willemoes-Suhm, there is one that undoubtedly represents this species, aud as the specimen 

 from wdiich the drawing was executed, according to the subjoined notes, must have been 

 very considerably larger than the ones examined by myself, and had, too, all its legs 

 uninjured, I have seen fit to reproduce the figure in the annexed cut. In his manuscript 

 notes, the late lamented naturalist has only recorded this interesting form as Thysano- 

 2)oda sp. ? — Unfortunately, the specimen has been lost, and hence the following descrip- 

 tion has been worked out in all essential particulars from the smaller ones, examined by 

 myself. 



Description. — The length of the specimen represented in PI. XIX. fig. 1, is 20 mm., 





»- 



H 



Fig. 4. Benthiuphaiisia amUyopx, G. 0. Sari!, n. gen. 



and that selected for anatomical investigation had very nearly the same size. Thi- 

 specimen examined by the late Dr. v. Willemoes-Suhm, and figured in the accompanpng 

 cut, was much larger, measuring, as stated by that author, not less than 48 mm. in length. 

 All|^three specimens were fem;iles. 



The form of the body (see PI. XIX. fig. 1, and accompanying cut) is somewhat 

 slender, and diff"ers from that in most other Euphausiidaj in being very little, if at all, 

 compressed, but nearly cylindrical throughout. 



The carapace has not a trace of lateral denticles, the inferior margins being quite 

 smooth and almost straight. The anterior part is defined posteriorly by a slight cervical 

 impression, and exhibits above, in the middle, a low keel, obsolete anteriorly. The 

 frontal margin projects in the middle as an acute angle extending above the bases of the 

 eyes, \vithout, however, forming any true rostrum. The antero-lateral corners of the 

 carapace are obtusely truncate. Posteriorly, the carapace forms a deep and narrow emargi- 

 nation, leaving, as usual, the dorsal part of the last segment of the trunk uncovered. 



