294 DISCOVERY REPORTS 



spines are present on the fourth and fifth somites. The postero-lateral spines of the 

 sixth are still present. 



(ii) With carapace having no posterior projection or, rarely, zvith a short stump 



remaining. 



Twenty-three specimens were found of which seven were closely examined. Their lengths are : 

 three of 11-5 mm., two of 12-0 mm., and one each of 12-5 and 13-0 mm. 



Of the twenty-three two of the smaller, 11-5 and 12-0 mm. long, retain short blunt 

 stumps of the posterior projection of the carapace. 



In the younger the lateral margins of the frontal plate are roughly parallel for only a 

 short distance at the base, beyond which they turn by rounded angles obliquely inwards 

 to make the distal part of the plate triangular. In the older the angles become at first 

 sharp, and then a forwardly directed spine arises from each, forerunners of the post- 

 ocular spines of the adult. The margins from the corners, or spines, to the base of the 

 rostrum are still denticulate. The rostrum most frequently reaches nearly to the end, 

 sometimes to or even beyond the end, of the second peduncular segment of the 

 antennule. 



The antennular spine is as long as or much shorter than the second segment of the 

 peduncle ; the lappet of the first segment is large and erect, and it is bifid in all but two 

 of the specimens, both of them 11-5 mm. long; there may or may not be a small spine 

 near the outer distal corner of the second segment. 



The postero-lateral spines of the sixth abdominal somite may or may not be present. 

 The telson may have one to four pairs of lateral spines. 



The sixteen specimens examined more superficially range in size from 12 to 15 mm. 

 Even in the largest of them the margins of the frontal plate are denticulate. 



Development of Euphausia spinifera 



Zimmer (1914, p. 429) recognized what he described as larval stages of E. spinifera, 

 compared the younger with the older and showed that the former were the same as 

 Euphausia schotti, Ortmann (Ortmann, 1893, p. 13, pi. vii, figs. 8, 8(7). Tattersall (1924, 

 p. 26) recognized two Furcilia stages and a post-larval stage and compared them with 

 those of £. longirostris. As already mentioned on p. 286 Illig (1930, pp. 504-7, text-figs. 

 183-190) described as E. longirostris a number of larvae which I was convinced must be 

 E. spinifera because they were all from the sub-tropical zone, from stations where the 

 surface temperatures varied from 15-9 to 17-1° C. I am indebted to Prof. A. Schellen- 

 berg of the Zoologisches Museum, Berlin, for the opportunity to examine some of Illig's 

 material. I saw those specimens from St. 90 described by Illig as ten females and seven 

 larvae, 10-4 mm. long. They are undoubtedly the following stages of E. spinifera: 



Furcilia, stage III: 2 specimens. 



Furcilia, stage IV: 2 specimens. 



Furcilia, stage V: i specimen. 



Furcilia, stage VI: i specimen (and almost certainly a second with a damaged telson). 



Post-larval stages, 9 specimens. 



