228 DISCOVERY REPORTS 



coldest Station. Some of Sars' four specimens came from near this locality in October 

 and the others also from sub-Antarctic water — from 48° 18' S, 130° 11' E (see Tattersall, 

 1924, p. 27), south of Australia. There is no obvious explanation for the presence of 

 E. spinifera in these places. The strikingly low salinities of the surface water at the four 

 stations south of the Pacific, and at the Challenger St. 289 in the same area, suggest that 

 there is a surface current of poorly saline water from the east. The hydrology of this 

 part of the sub-Antarctic Zone is not well known, but the surface currents appear to be 

 exceptional. 



lUig's records of E. spinifera (1930, p. 503) include some from north-west of Cape 

 Blanco on the west coast of North Africa. I have been allowed to examine the speci- 

 mens by Dr Schellenberg of the Zoologisches Museum, Berlin, and I find that they 

 are not E. spinifera. They are all immature (I could not find the male which was 

 recorded), and I think they are E. hatiseni} 



E. spinifera has not been found north of the subtropical Zone. In April and May 

 193 1 a line of closely placed stations was made up the west- Atlantic along the 30th 

 meridian to 15° N (Station List, 1 929-1 931, Discovery Reports, iv). Dr Kemp examined 

 the Euphausians taken in the upper 200-300 m. of water by means of an oblique haul 

 with a large stramin net at each of those stations. E. spinifera was taken only in the 

 colder part of the subtropical Zone. A similar series of hauls was made down the 

 west Atlantic in October of the same year, and I examined some, but not all, of the 

 Euphausians in each haul. I found E. spinifera in the warmer part of the subtropical 

 Zone only. 



It is then a circumpolar subtropical species which is sometimes found some little 

 distance within the sub-Antarctic Zone. 



Euphausia longirostris, Hansen (Figs. 20-22, 28 c) 



E. longirostris, Hansen, 1908, p. 4, pi. i, figs, i a-c; 1913, p. 35, pi. v, figs. 3 a-d; Tattersall, 

 1913, p. 877; Zimmer, 1914, p. 429, pi. xxvi, figs. 65 and 66; Tattersall, 1924, pp. 22-26, pi. i, 

 figs. 1-7, pi. ii, figs. 1-4; Rustad, 1934, pp. 41-2; Hardy and Gunther, 1935, p. 207, fig. 94. 



Peneus{})—Zoez, Dohrn, 1871, p. 375, pis. xxix and xxx, figs. 54-61 (larva). 



Euphausia sp., Sars, 1885, p. 170, pi. xxxi, figs. 30 and 31 (larva). 



Not E. longirostris, Illig, 1930, pp. 504-7, figs. 183-90. 



Description. The rostrum is strong and very long, reaching as far forward as the 



1 The youngest stage among them with a complete telson was one with three terminal spines. It differed 

 in the following ways from the same stage of E. spinifera (compare p. 301): the frontal plate was a broad 

 triangle, with denticulations on the margins so fine that they were difficult to see, and with a very small 

 rostral spine ; there was no trace of a posterior projection on the carapace ; the third segment of the antennular 

 peduncle carried on its upper side at the distal end a strong upwardly and forwardly projecting spine; the 

 spine from the third abdominal segment was two-thirds the length of the fourth segment. The older specimens 

 were early post-larval stages. The frontal plates of all were such as might be expected to develop from that 

 of the furcilia with three terminal spines and unlike those of E. spinifera of the same size. All had a spine on 

 the upper distal end of the third segment of the antennular peduncle; in the older of them it was obviously 

 a part of the dorsal keel and gave it the characteristic shape it has in adult E. luiiiseni (Fig. i8«). The larger 

 had hepatic spines. 



