2 Messrs. E. W. L. Holt and AV. M. Tattcrsall on 



thoracic limbs. Thus, the maxillipede or first maxilhpede 

 is termed the " first thoracic limb " and its endopod the 

 "first thoracic leg," and so on. 



Fam. EuphausiidaB. 

 Genus Euphausia, Dana. 



Euphausia superba, Dana, 1852. 



E. superha, G. 0. Sars (1885). 

 E. Murrayi, G. O. Sars (1885). 

 E. atitarctica, G. 0. S.-xrs (1885). 

 E. (pacialis, Ilodgsou (1902). 

 E. 'aiistralis, Hodgson (1902). 



Of the five supposed species mentioned above E. superba 

 is the adult male, E. Murrayi and E. aiistralis apply alike to 

 the adult female and nearly adult male, while E. glacialis 

 and E. antarctica represent youthful stages in which the 

 larval characters are not wholly lost. The supposed dis- 

 tinctions arise from errors in Sars's descriptions and figures 

 of all except the adult male. 



E. antarctica is described as having no lateral denticle on 

 the carapace. The type specimen has the side from which 

 Sars took his drawing injured, but the denticle is perfect and 

 quite conspicuous on the other side. It is a young form 

 with the spine on the outer distal angle of the antennular 

 peduncle well developed, as is usual in young Euphausia. 

 ' Discovery ' specimens lead from the E. antarctica stage to 

 E. glacialis, Hodgson, in which the spine on the basal joint 

 of the antennular peduncle has been reduced to about the 

 adult proportions, while the lappet on the dor.^al distal edge 

 of the same joint is beginning to appear. At about 27 mm. 

 specimens in other respects agreeing with E. glacialis have 

 practically assumed the actual form of E. Murrayi. 



The type of E. Murrayi differs from Sars^s description and 

 figures in the following particulars, which bring it into 

 harmony with Hodgson's types of E. aiistralis : — 

 (i) It has a pre- anal spine. 



(ii) It has a small rather blunt spine at the outer distal 

 corner of the first joint of the antennular peduncle. 



(iii) It has a spine at the extremity of the outer margin 

 of the antennal scale. 



(iv) The extremity of the pleural plate of the fifth segment 

 of the pleon is rounded rather than pointed. 



E. Murrayi may reach 45 mm., but gradations of form 



