THE SOUTHERN GROUP 



251 



two things in common which may show a closer relationship between them than they have with the 

 other three : the foremost membranous lobe on the proximal process is set far back beneath the 

 secondary process, not more distally than it as in E. hicens, E. vallentini and E. frigida; the lateral 

 process has no secondary tooth. The two species have other similarities, which are at the same time 

 differences from E. lucens, E. vallentini and E. frigida: they are the only ones of the group in "which 

 the carapace has a cervical groove and is keeled anteriorly in the mid-dorsal line, and in which it is 

 produced into a well-marked projection behind each eye; the rostral projection is stronger in them 

 than in the other three (Fig. 31). Although the first segment of the antennular peduncle has an 



bed e 



Fig. 31. Front part of carapace of the species of the southern group: a, E. lucens, x 12; b, E. vallentini, 

 X 12; c, E. frigida, x 12; d, E. superba, x 10; e, E. crystallorophias, x 12. 



b c d, dp e 



Fig. 32. Ends of the basal segments of the left antennular peduncles of the species of the southern group 

 showing lappets and spines, from above, a, E. lucens; b, E. vallentini; c, E. frigida; d, E. superba; e, E. crys- 

 tallorophias. a, x 18; b, c and e, x 12; di, x 10; dz, x ii. 



enormous lobe in E. superba and none in E. crystallorophias, it may have in the former, and it always 

 has in the latter, a spine on the outer distal corner such as is not found in adult E. lucens, E. vallentini 

 or E. frigida (Fig. 32).^ If these are evidences of affinity then the group of five species falls into two 

 divisions corresponding with the order of their occurrence from north to south — a northerly and a 

 southerly division. 



The copulatory organs of the northerly species have some features which suggest that their re- 

 lationship is in the order E. lucens, E. vallentini, E. frigida — which is that of their occurrence from 

 north to south. E. vallentini, the middle member, shares with each of the end members a character 

 not possessed by the other: the two parts into which the end of its terminal process are cleft are 

 blunt and rounded as in E. lucens, not flattened with one part lobed and the other serrated as in 

 E. frigida; but, like E. frigida and unlike E. lucens, its lateral process has a tiny projection near the 

 axil of the distal tooth. It stands midway between them in the proportional lengths of the terminal 



^ Or in any other species in the genus. 



8-2 



