Cumacea: 15. Ekdiastylidae, 1. Ekdiastylis 137 



the 2^^, but with spines ou medial margin respectively 2 and 3. L. g juv. 

 scarcely 8 mm. 



Off Portugal ;lat 380 yjsf.^ long. 9o 18' W., depth 1036 m; W. of Shetland, 4—6 ni. 



4. E. mystaeinus (O. Sars) 1887 Diastylis mystacina, G. O. Sars in: Rep. Voy. 

 Challenger, v. 19 pars 55 p. 9,60 t. 10 f. 1—3 | 1912 Ekdiastylis mystaeinus, T. Stebbing 

 in: Ann. S. Afr. Mus., v. 10 v p. 155. 



Pseudorostral lobes shortly and horizontally produced in front of the 

 small rounded eyeless eyelobe, each with apical denticle and strongly but 

 irregularly dentate crest continued as pair of slightly flexuous carinae on 

 front of carapace; no antero-lateral corners: surface of large tumid carapace 

 microscopically spicate, lower margin anteriorly serrate. Pedigerous seg- 

 ments 1 and 2 with front margin denticulate, 3'^ with transverse dorsal 

 carina, ^^^ with paii* of medio-dorsal longitudinal serrate carinae, 5*'^ with 

 pair of dorsal denticles; first 3 pleon segments similarly armed; telson for 

 little more than proximal half cylindric. rest slightly tapering to apical pair 

 of stout spines; only 1 lateral pair, with a spinule above on left side of the 

 specimen. Peraeopods 1 and 2 with 2"^ joj^t densely spinose. Peduncle of 

 uropods rather shorter than telson. without spines on medial margin, the 

 endopod about half as long as peduncle, considerably shorter than the exopod, 

 its 2 subequal joints armed respectively with 1 and 2 lateral spines. L. Q 

 with marsupium, about 10 mm. 



N. Atlantic, lat. 36 21' K, long. 230 31' W., depth 3700 m. 



5. E. hexaceros (Zimmer) 1908 Diastylis h., Zimmer in: Ergeb. Tiefsee-Exp., 

 c. 8 p. 158, 187 t. 44 (9) f. 93—95 | 1910 D. /i., T. Stebbing iu: Ann. S. Afr. Mus., r. 6iv 

 p. 418 I 1912 Ekdiastylis h., T. Stebbing in: Ann. S. Afr. Mus., v. lOv p. 155. 



Pseudorostral lobes well produced horizontally in front of the small 

 rounded eyeless eyelobe, with 3 submarginal denticles but no apical denticle. 

 Carapace large, with a pair of lateral processes in advance of the eyelobe, 

 a larger pair to the rear of it, and a pair still larger and much wider apart 

 to the rear of the frontal lobe; much of the lower margin serrate, surface 

 scabrous with microscopic denticles. Pedigerous segment 3 with submedian 

 pair of conical bosses. 4*'^ with a pair of dentate longitudinal carinae. 5^'^ with 

 a pair of denticles. Pleon segment 1 begirt with several denticles: the next 

 2 segments having only 2 pairs, and the 2 following a single pair a-piece. 

 Telson for rather more than half its length cylindric, then tapering with 

 5 spines on one side and G on the other. Colour white, pellucid. L. o with 

 well developed marsupium about 10 mm. 



5. Africa, outside the Agulhas Bank, lat. 39o 9' S., long. 18" 32-8' E., depth 565 in. 



6. E. argentatus (Calm.) 1912 Diastylis argentata, Caiman in: P. U. S. Mus., 

 f. 41 p. 605, 649 tf. 70— 75 | 1912 Ekdiastylis argentatus, T. Stebbing in: Ann. S. Afr. 

 31us., V. 10 V p. 155. 



Pseudorostral lobes horizontally produced in front of the minute tri- 

 angular eyeless eyelobe, slightly denticulate above and notched at the l)ase; 

 carapace with pitted surface, oblique line of denticles on each side of the 

 pseudorostrum, with small procurved tooth submarginal, about one-third of 

 the length from the front, followed in the 9 by a serrate carina reaching 

 the hind margin; lower margin anteriorly serrate. Pedigerous segments 2, 3, 

 with side-plates more or less serrate, last 3 segments with some dorsal 

 denticles, 5*^ segment with postero-lateral lobes rounded in 9, bifid in d. 



