Cumacea: 21. Dicidae, 1. Die, 22. Gynodiastylidae, 1. Gynodiastylis 161 



2. D. tubulieauda (Calm.) 1905 DiastyUs t., Caiman in: Sci. Invest. Fish. 

 Ireland, 1904 app. 1 p. 10, 16 t. 5 f. 82— 86 | 1910 Die ? t., T. Stebbiug in: Ann. S. Afr. 

 Mus., i\6iv p.416 I 1912 D. t., T. Scott in: Sci. Invest. Fish. Scotl., 1911 nr. 1 p.4 1. 1 

 f. 6 I 1912 D. t., T. Stabbing in: Ann. S. Afr. Mus., v. lOv p. 147. 



Pseudorostral lobes acute, prominent, horizontal. Carapace spinulose. 

 Pedigeroiis segments 3, 4, quite distinct one from the other. Telson as 

 long as the 4 preceding segments combined, apex sharply triangular, with 

 2 apical spinules. Peraeopods 3, 4, very long. Peraeopod 5 quite wanting, 

 probably a juvenile character. Peduncle of uropods ^/g^^ as long as telson, much 

 less than twice the exopod, but considerably more than twice the endopod, 

 which has 2, 1, 1 spines respectively on medial margin of the 3 joints, and 

 2 apical spines. L. juv., 5*4 mm, sex doubtful. 



Ireland, County Mayo, 77 miles W. N. W. of Achill Head, depth 699 m; lat. 59*> 

 25' N., long. 70" 33' W., depth 1100 ra. 



22. Fam. Gynodiastylidae 



1912 Gynodiastylidae, T. Stebbing in: Ann. S. Afr. Mus., i". lOv p. 133, 146. 



Telson of moderate size, with no apical spines or 2 that are rudimen- 

 tary. Accessory flagellum of 1st antenna very small. Second antenna small 

 in both sexes. Palp of maxilla 1 with 2 filaments. Branchial leaflets few or 

 wanting. Maxilliped 3 without exopods in the female. Peraeopods 1—4 or only 

 1^* and 2"<^ in the male with exopods, and only 1^* and 2"*^ in the female. 

 No pleopods in the male. Uropods with the endopod two-jointed or simple. 



1 genus. 



1. Gen. Gynodiastylis Caiman 



1911 Gynodiastylis, Caiman in: Tr, zool. Soc. London, i'. 18iv p. 312, 366 1 1912 

 <?., T. Stebbing in: Ann. S. Afr. Mus., v. 10 v p. 146. 



At present with the characters of the family. 

 4 species. 



Synopsis of species: 



I Uropods with the endopod simple . 1. G. laevis 



\ Uropods with the endopod two-jointed — 2. 



f Uropods with first joint of endopod longer than second . 2. G. carinatus 



\ Uropods with first joint of endopod not longer than second — 3. 



1 Carapace with numerous longitudinal ridges 3. G. costatus 



\ Carapace with a pair of dorso-lateral ridges ....... 4. G. bicristatus 



1. G. laevis Calm. 1911 G. I., Caiman in: Tr. zool. Soc. London, v. 18 iv p. 342, 

 367,371 t. 35 f. 32—39 | 1912 G. I, T. Stebbing in: Ann. S. Afr. Mus., v. lOv p. 147. 



Pseudorostral lobes short, slightly deflexed, apically truncate, sinus 

 slightly defined by tooth in g, by rounded prominence in d. Surface of 

 carapace quite smooth, eyelobe slightly prominent. Pedigerous segment 1 

 very short, 2°*^ very long, with side-plate produced anteriorly as a narrow 

 lobe, 3"i and 4*^^ with side plates extended backwards. Pleon with faint 

 lateral keels, 6**^ segment little shorter than 5**1; telson little more than half the 

 length of the preceding segment. Eyelobe shows neither pigment nor distinct facets. 

 Antenna 1 short, 2"^ joi^t of peduncle about -//« of 3^, the small flagella 

 each 3-jointed in Q, the principal 4-jointed in the c5. Antenna 2 of d 



Das Tierreich. 39. Lief.: T. R. R. Stebbing, Cumacea. il 



