136 Cumacea: 15. Ekdiastylid'ae, 1. Ekdiastylis 



3 pedigerous segments are extended backwards laterally, causing in the 

 ovigerous Q a wide separation between the 2"" and 3*^ peraeopods; hinder 

 angles of the 5*^ segment obtuse, more extended in d than in Q . Telson 

 shorter than peduncle of the uropod, much in Q, a little in (S, the slender 

 post-anal part having about 7 pairs of lateral spines in the 9 , a dozen in 

 the (5. Eye distinct. Antenna 1, 2^^^ joint of peduncle the shortest, principal 

 flagellum 4-jointed in 9, 5- or 6-jointed in 6, accessory 2- or 3-jointed. 

 Antenna 2 of 9 of five small joints, the last minute. Maxilliped 1 with 

 about a score of branchial elements in twisted series on the epipod. Peraeo- 

 pod 2 with 5*h joint not quite equal to length of 6*^ and 7*'^ joints com- 

 bined. Rami of pleopods very short. Peduncle of uropods longer than the 

 rami, its medial margin with about 20 spines in o , 30 to 40 in 6 . exopod 

 longer than endopod, of which the P* joint is shorter than the 2°*^. with 

 respectively 7 and 10 spines on medial margin of 9 , 11 and 18 in d, but 

 the numbers variable. L. Q about 9 mm, d about 10 mm. 



N. America, from Gulf of St. Lawrence to Loog Island, surface to 347 m. 



2. E. politus (S. I. Sm.) 1879 Diastylis p., S. I. Smith in: Tr. Connect. Ac, 

 v.oi p. 108 I 1900 D. p., Zimmer in: Fauna arctica, v.l p. 423 | 1912 Ekdiastylis j^-r 

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



Agreeing with E. sculptns except that the areolations of the cara- 

 pace are fewer, less deep, and not extending to the postero-lateral portions. 

 Pedigerous segments 1. 2, in near agreement with E. sculptus, 3 — 5 more 

 nearly with those of Diastylis rathkii (p. 98). Telson with slender distal 

 section scarcely longer than the basal, with (i — 9 pairs of lateral spines 

 in 9, 8 — 10 in the 6. Peraeopod 2 with 5*^^^ joint nearly twice as long 

 as 6*^ and 7*^ joints combined. Peduncle of uropods longer than the telson 

 and also than the rami, of which the exopod is the longer; endopod with 



4 spines on medial margin of 1^* joint in 9, 4—6 on the lanceolate 2"'*. 

 in the 6 with 24 — 30 spines, of which 10 — 12 are on the P^ joint. Colour 

 of 6 whitish, pellucid, with pink eyelobe. L. 9 12 mm, 6 14 mm. 



N. America, Gulf of St. Lawrence to Vineyard Sound, surface to 347 m. 



3. E. insignis (0. Sars) 1871 Diastylis i, G. 0. Sars in: Ofv. Ak. Forh., r. 28 

 nr. 1 p. 76 | 1871 D. i., G. O. Sars in: Svenska Ak. Handl., n. ser. v.9 nr. 13 p. 34 t. 14 

 f. 68— 71 I 1879 D.i., A. M. Norman in: Ann. nat. Hist., ser. 5 v.3 p. 55 I 1905 D. i.. 

 Caiman in: Sci. Invest. Fish. Ireland, 1904 app. 1 p. 10, 12, 44 | 1912 Ekdiastylis i., 

 T. Stabbing in: Ann. S. Afr. Mus., ?'. 10 v p. 155. 



Pseudorostral lobes in front of small eyeless eyelobe horizontal, rather 

 long, acute, with 2 apical spinules, antero-lateral corners rounded, serrulate. 

 Carapace large, tumid, laterally reticulate with short rows of tubercular spinules^, 

 in front having on each side a strong sul)ventral forward pointing spiniform 

 process. Pedigerous segments narrow, first concealed except dorsally. side- 

 plates of the rest small, ii-regularly emarginate or divided into spiniform 

 processes, the last 3 spinose at hind margin and having a large pair of 

 dorsal teeth, the 5*'' postero-laterally bifid. Pleon segments densely aculeate. 

 Telson longer than peduncle of uropods, basal two-thirds broad, subcylindric. 

 with 6 or 7 denticles on each side, the tapering end with single pair of 

 lateral spines close to the apex and a much larger apical pair. Antenna 

 1 small, last 2 joints of peduncle subequal. Peduncle of uropods much 

 longer than the rami, with few spines on the medial margin; exopod con- 

 siderably longer than the endopod, in which the 1^* joint is longer than 



