96 



Cumacea: 11. Diastylidae, 1. Diastylis 



2"*^ and 3*^ combined, spines on the 3 joints respectively 6, 5, 3 (Sars), for 

 2"^^ joint 3 or rarely 4 (Smith). Colour pale carneous, with reddish purple 

 patch on carapace, and 2 small spots of pink. L. 9 nearly 11 mm. 



N. America, from Gulf of St. Lawrence to lat. 35 •* 42' N., near Cape Hatteras, 

 depth 4—373 m. 



13. D. cornutus (Boeck) 18.59 D. bispinosa, Danielssen (non Stimpson, 1853) 

 in: Norske Selsk. Skr. 19. Aarh., d. 4ii p. 108 | 1864 Cunia cornuta, A. Boeck in: 

 Forh. Selsk. Christian., 1863 p. 190 | 1865 Diastylis bicornis, Bate in: Ann. nat. Hist., 

 ser.3 t;.15 p. 84 1. 1 f.2 | 1865 D. bispinosa, G. 0. Sars in: Forh. Selsk. Christian., 1864 

 p. 164 I 1865 D. cornuta, Bate in: Zool. Rec, 1864 v.l p. 287 | 1866 D. bispinosus. 

 Bate in: Zool. Rec, 1865 v.2 p. 326 | 1879 D. cornuta, A.M.Norman in: Ann. nat. 

 Hist., ser. 5 «;. 3 p. 55 | 1883 D. cornutus, G. 0. Sars in: Forh. Selsk. Christian., 1882 nr. 18 

 p. 12, 58 I 1894 D. c, A.M.Norman in: Ann. nat. Hist., ser. 6 v.1'6 p. 276 | 1900 Z>. cornuta, 

 G. 0. Sars, Crust. Norway, v. '6 p. 45 t. 35, 36 | 1900 D. c, Zimmer in: Fauna arctica, 

 V. 1 p. 421,434 I 1909 D. c, A. M. Norman & G. S. Brady in: Nat. Hist. Tr. Northumb., 

 ser. 2 v.3u p. 31. 



Nearly allied to IJ. bispinosus, but pseudorostral lobes less produced, 

 the antero-lateral corners distinct, though obtusely angled; the two pairs of 



Fig. 55. 

 D. cornutus (cj) (Boeck), 

 branchiae (after Sars). 



Fig. 56. 

 D. cornutus (Boeck), 

 pleopod 1 (after fears). 



Fig. 67. 

 D. cornutus (Boeck), 

 pleopod 2 (after Sars). 



teeth which flank the frontal lobe of the carapace are in the 9 more 

 conspicuous, and are followed by 2 meandering rows of small unequal 

 denticles: in the d the pseudorostral lobes are minutely serrate at each 

 side, the antero-lateral corners produced as rounded dentate lobes close to 

 the eye, an obliquely transverse fold in the front part of the carapace on 

 each side joins the serrate lateral carina which runs to the hind margin, the 

 carapace being otherwise almost smooth. Pedigerous segments with spinules 

 dorsally in double row in 9, not in d, 5*^ segment in 9 with a median 

 spinule on the hind margin, the posterolateral angles acute, less produced 

 in 9 than in d. Pleon clothed with spinules. Telson shorter than peduncle 

 of uropods, with 8 — 10 pairs of lateral spines. Eye small, imperfectly deve- 

 loped. Antenna 1, S*^ joint longer than 2'^'^, P* not equal to 2^^ and 3'^ 

 combined, margin denticulate. Peraeopod 1, with 5*^ joint nearly, 6*^ more 



