Mr. E. J. Miers on Arctic Crustacea. 99 



Onesimus Edimrdsii. PI. III. fig. 3. 



Anonyx Edioardsii, Kroyer, Naturh. Tidsskr. 2 E.. ii. pp. 1, 41 (184G) ; 



Voy. en Scaud. Crust. Atlas, pi. xvi. fig 1. 

 Lysiimassa Edwardsii, Goes, (EtV. Vet. Ak. Forhandl. p. 520 (1865). 

 Onesimus Edwardsii, Boeck, Forhandl. Vidensk. Selsk. Christiania, 



p. 113 (1871); Skandin. og Arktiske Amphip. ii. p. 107, pi. vi. 



fig. 4 (1876). 



Coll. Feilden : Discovery Eay, at 5| fathoms, lat. 81° 44', one 

 specimen ; Floeberg Beach, at 10 fathoms, males and females, abun- 

 dantly. 



The eyes in the specimens that I refer to this species are large, 

 red, and subreniform when present; but are in some specimens 

 scarcely distinguishable, and in others entirely absent. The first 

 joint of the flagellum of the superior antennae is short, not exceeding 

 in length the two or three following joints taken together, or even 

 less, and not quite equalling in length the first joint of the accessory 

 flagellum. In the first pair of legs the palm is but little longer than 

 the wrist and obliquely truncate ; the second pair of legs has a 

 short, distally enlarged and truncated palm and small arcuate 

 finger in both sexes. The third joint of the last three pairs of legs 

 is not dilated, the fifth joint a little shorter than the two preceding 

 taken together ; the rami of the last pair of uropoda are very short, 

 about as long as the terminal segment. The antero -lateral angle of 

 the head is considerably produced anteriorly. The third segment 

 of the postabdomen is slightly produced upward and subacute 

 at its postero-lateral angle ; the terminal segment is broadly semi- 

 oval, with a raised marginal line, very slightly emarginate at its 

 distal extremity, but without a median fissure. The whole animal 

 is coarsely punctulated. 



Of this species adult examples of both sexes were collected ; of 

 sixteen specimens from Floeberg Beach, in spirits, six are males. Of 

 the females, one example only bears ova. Length of the largest 

 male nearly 10 lines (21 miUims.) ; of the largest female 11 lines 

 (231 millims.). 



The specimens collected differ from Boeck's diagnosis in one par- 

 ticular ; the third segment of the postabdomen is slightly produced 

 upward at the postero-lateral angle. Nothing is said of the form 

 of this segmeat by Kroyer in his description of the species or in the 

 Latin diagnosis that follows. In Kroyor's figure of the species in 

 the Atlas of the ' Voyage en Scandinavie,' the postero-lateral angle 

 of this segment is represented as not produced upward, but acute. 

 There is, however, a manifest inconsistency between the diagnosis 

 of Boeck and the figures in the Atlas referred to ; e. g. in Onesimus 

 plautiis the third postabdorainal segment is described by Boeck as 

 " sursum productus acutus," but figured by Kroyer as broadly ob- 

 tuse and rounded at the postero-lateral angle. 



Onesimus Edwardsii has been recorded from Greenland, Spitzber- 

 gen, and Britain. 



7* 



