16 . W. M. TATTERSALL. 



D'Arcy W. Thompson, from the collections of the University College, Dundee, appear 

 to belong to this species. They were collected in the Antarctic Ocean, the exact 

 locality being uncertain, but it is believed to be in the neighbourhood of the South 

 Shetland Islands. 



EUPHAUSIA, sp. ?, juv. 



(PI. IV., Figs. 7-9.) 



Localities of captures: — Lat. 49° 40' S., long. 172° 18' 30" W., five specimens, 

 immature, 8-9 mm. 



Lat. 58° 49' 45" S., long. 154° 48' W., three specimens, immature, 10 mm. 



The specimens from the above two localities all belong to the same species. They 

 were submitted to Dr. H. J. Hansen of Copenhagen, who agreed with my suggestion 

 that they were too young for absolute specific determination. I give here only a brief 

 description, pointing out a few of the characteristic features. 



Carapace with a prominent slender denticle on lateral margins just over the base 

 of the third thoracic limbs ; antero-lateral margins slightly undulate, only partially 

 concealing the eyestalks and produced into a long, narrowly acute rostrum (Fig. 7) 

 extending almost to the anterior end of the eye and about half-way along the basal 

 joint of the antennules. 



Pleon having the third segment provided dorsally on the median posterior margin 

 of the tergum with a slender spine (Fig. 9) ; sixth segment long and slender, about 

 twice as long as the fifth. 



Antennular peduncle (Figs. 7 and 8), with a minute bluntly pointed simple lobe 

 on the inner distal corner of the basal joint ; a thin oblique lamella-like ridge running 

 across the third joint from the inner proximal to the outer distal corner and partly 

 continued down the inner side of the second joint. 



Antennal scale reaching to about half-way along the terminal joint of the 

 antennular peduncle. 



Telson having the portion beyond the sub-apical spines produced into an acute 

 apex with smooth margins ; two pairs of spinules present. 



Uropods reaching to the level of the insertion of the sub-apical spines. 



This species belongs to that section of the genus provided with a spine on the 

 dorsal surface of the third segment of the pleon. Among members of this section it 

 approaches most nearly to E. gibhoides, Ortmann (1893), but Dr. Hansen has kindly 

 pointed out to me that it differs from that species in the much greater length of the 

 rostrum and its different shape. 



The smallest of the specimens, i.e. all under 9 mm. in length, have the spine on 

 the third pleon segment still undeveloped, only the two largest ones, 9*5 mm. and 

 10 mm. in length, showing it fully formed. We have here slight evidence as to the 

 stage in development at which this spine appears. None of the specimens present any 

 larval characters in the form of the telson or antennules. It would appear, then, that 



