Hyale 569 



Segments of body imbricated, integument firm. Side-plates with lower 

 margin slightly crenulate. Pleon segment 3, postero-lateral corners quadrate^ 

 but not acutely. Eyes of moderate size. Antennae 1 and 2 in Q subequal. 

 In d antenna 1 considerably shorter than antenna 2, but reaching much beyond 

 peduncle of latter, flagellum longer than peduucle, with 11 joints, most of 

 tbem distally widened. Antenna 2 in d, ultimate and penultimate joints of 

 peduncle subequal, flagellum 15-jointed. Gnatbopod I in d, 5*^ Joint in adult 

 strongly produced along bind margin of 6*^, 6**^ oblong, surface not far from 

 base armed with a broad spine, distal part of bind margin fringed witb 

 spinules, palm transverse, rounded off but aimed with a stout spine, finger 

 matchiug palm. Gnatbopod 2 in d, 6*^ Joint robust, broadest proximally, 

 front very convex, bind margin uearly straight, with small spinulose notch, 

 palm slightly oblique, with small cavity not far from hinge, well defined, 

 bordered with spinules and setules and having 2 palmar spines in a terminal 

 cavity, the finger closing down on the inner side of these spines. Gnatbo- 

 pod 1 in o , 5*^^ Joint distally wider than 6**^, 6*^ oblong, with spinules at 

 notch of bind margiu and also at apex, palm slightly oblique. Gnatbopod 2 

 in 9 similar to gnatbopod 1, but larger, 5**^ Joint more produced. Peraeo- 

 pods 1 — 5 robust, 6**^ Joint carrying a large, straight, subapical spine, sen'ate, 

 tipped with a little hook, and opposable to the strongly curved finger; nearer 

 the base the 6*^ Joint has a much smaller spine and at the apex one resembling 

 the subapical, on a much smaller scale. Peraeopods 3 — 5, 2*^ Joint broadly 

 expanded. with crenulate bind margin, 6*^ Joint with bind margin unarmed. 

 Uropod 1, outer ramus ratber shorter than inner, both with marginal spines. 

 Uropod 3, ramus a little shorter than peduncle, with apical spinules. Telson 

 divided into 2 obtuse-ended lobes, which have their surfaces adjacent. Colour 

 bluish grey or almost black, or yellowish, or darkish green. L. 7 mm. 



North- Atlantic and North-Sea (England, France, West-Norway) ; Mediterranean 

 (Algeria). 



17. H. media (Dana) 1853 & 55 Allorchestes tn., J. D. Dana in : U. S. expl. Exp., 

 r.lSii p.898; t.61 f.4a— g, 1— n I 1862 A. tnedius, Bäte, Cat. Amphip. Brit. Mus., p. 46 

 t.7 f.9 I 1879 Hyale (A.) media, Wrze&üiowski in: Zool. Anz., u 2 p. 200 | 1 89'd H.pontica 

 (part.), A. DellaValle in: F. Fl. Neapel, ».20 p. 524. 



Side-plates 1 — 5 wide, not deep. Pleon segment 3, postero-lateral 

 corners quadrate, scarcely produced. Eyes apparently variable in shape and 

 size. Antenna 1, peduncle short, flagellum 10 — 14-jointed. Antenna 2^ 

 ultimate Joint of peduncle ratber longer than penultimate, both ratber short, 

 flagellum 16-jointed. Gnatbopod 1 in d, 2* Joint strongly widening from 

 very narrow base, 5**^ with rounded fringed lobe, not produced along the 6*^, 

 6*^ oblong, margins parallel, hinder with median spinules, finger a little 

 overlapping slightly oblique palm. Gnatbopod 2 in 6,2^ Joint distally widened^ 

 3*^ lobed in front, 6^^ large, subovate, widest before reaching the oblique well 

 defined palm. Gnathopods 1 and 2 in Q about as in H. rubra (p. 572). Peraeo- 

 pods 1 — 5 robust, finger curved, inner setule minute. Peraeopods 1 and 2, 

 6*^ Joint having on inner apex a stout, smooth spine, which is widest at its apex. 

 Peraeopods 3—5 with a very large submedian sen-ate spine, like that which 

 is a distinguishing feature in H. pontica, but higher up on the margin; at 

 the apex a small spine curves towards the smooth finger. Peraeopods 3 

 and 5, 2*^ Joint rotund, in peraeopod 5 very broad; peraeopod 4, 2"^ Joint 

 tending to oblong; in all 3 the bind margin nearly smooth, except for one 

 pronounced indent. Pleopods with 2 short broad coupling hooks and 



