The Sympoda. 155 



FAMILY EKDIASTYLID^, n. 



This family is distinguished from the restricted Diastylidae by 

 having the inner ram us of the uropods two-jointed. 



EKDIASTYLIS, n. g. 



With the character of the family. 



The species allotted to this genus are E. sculptus, E. insignis, 

 E. abbreviatus, all assigned to Diastylis by Sars in 1871 ; E. fim- 

 briatus (Sars), 1873 ; E. politics (S. I. Smith), 1882 ; E. horridus 

 (Sars), 1887; E. mystaciiius (Sars), 1887; E. hexaceros (Zirnmer) 

 1908 ; and E. <ir</<>ntatus (Caiman), 1912. 



EKDIASTYLIS HEXACEROS (Zimmer). 



1908. Diastylis hexaceros, Zimmer, Deutsch. Tiefsee-Exp., vol. viii. 



p. 187, pi. 44, figs. 93-95. 

 1910. D. h., Stebbing, S.A. Crustacea, pt. 5, Annals S.A. Mus. 



vol. vi., p. 418. 



I have not myself met with this species, which was taken by the 

 German Expedition outside the Agulhas Bank in a depth of 565 m. 



FAMILY LEUCONID^. 



LS79. Leuconidce, G. O. Sars, Arch. Naturv. Kristian., vol. iii., p. 6, 



vol. iv., p. 74. 

 1900. L., Sars, Crustacea of Norway, vol. iii., p. 28. 



All the pedigerous segments distinct ; telson wanting ; eye want- 

 ing ; first antenme with accessory flagellum small ; mandibles 

 broad at the base, spines few ; first maxillae with unisetose palp ; 

 bi-anchial leaflets few ; exopods on first four pairs of peraeopods in 

 the male and the first three in the female ; two pairs of pleopods 

 in the male ; inner branch of uropods two-jointed. 



To this family are assigned the genera Leucon, Kroyer, 1846 ; 

 Eiulorella, Norman, 1867 ; Endorellopsis, Sars, 1882; and Pseudo- 

 leucon, Zimmer, 1903. From it are detached the three genera 

 Paraleucon, Heinileucon, and Heteroleucon, all instituted by Dr. 

 Caiman in 1907. The first of these I take as representative of a 



