Cressa 191 



1. Gen. Cressa ßoeck 



1857 Danaia (Sp. un.: D. dubia) (uon H. Milne Edwards & Haime 1855, Authozoa!),. 

 Bäte in: Ann. nat. Hist., ser. 2 v. 19 p. 137 | 1871 Cressa, A. Boeck in: Forh. Selsk. 

 Christian., 1870 p. 145 ! 1890 C, J. Bonnier in: Bull. sei. France Belgique, «.22 p. 186, 191 | 

 1892 a, G. 0. Sars, Crust. Norway, vA p.277 j 1893 C, A. DellaValle in: F.Fl. 

 Neapel, i'.20 p. 580. 



Antenna 1 much longer than antenua 2. Gnathopod 1 slender and 

 feeble, Peraeopods 1 — 5 slender. Telson acute at apex. 



3 species. 



Synopsis of species: 



J Some of the segments dorsally dentate 1. C. dubia . . . p. 191 



\ None of the segments dorsally dentate — 2. 



J Byes present 2. C. minuta . . p. 192 



Eyes wanting 3. C. abyssicola . p. 192 



{ 



1. C. dubia (Bäte) 1856 Montagua dubitis (nom. nud.), Bäte in: Rep. Brit. 

 Ass., Meet. 25 p. 57 | 1857 Danaia dubia, Bäte in : Ann. nat. Hist., ser. 2 v. 19 p. 137 

 1876 D. d., T. Stebbing in: Ann. nat. Hist., ser. 4 «.18 i).444 1. 19 f. 2 ] 1888 Cressa d., 

 T. Stebbing in: ßep.Voy. Challenger, u 29 p. 293 | 1890 Cd. (part.), J. Bonnier in: 

 Bull. sei. France Belgique, «.22 p. 186 t. 10 \ 1892 C. d., G. 0. Sars, Crust. Norway, v.l 

 p.278 t. 98 f. 2; t. 99 f . 1 ] 1893 Cd. (part.), A. DellaValle in: F. Fl. Neapel.' y. 2a 

 p. 581 t. 58 f. 85 I 1871 C. schi0dtei, A. Boeck in: Forh. Selsk. Christian., 1870 p. 145. 



Head, lateral corners acutely produced, with a small tootli below and 

 to the rear of the principal projection. Peraeon segments 6 and 7 and pleon 

 segments 1 and 2 produced backward in a curved tooth. Side-plates 2 and 3 

 with 4 or 5 coarse serratious curving forward at lower bind corner; 4*^ 

 emarginate behind, angle of emargination acute. Pleon segraent 3, postero- 

 lateral corners much produced. Eyes large, oval, dark red. Antenna 1, P* Joint 

 long, rather longer than 2^, both triangularly produced at apex, flagellum 

 slender, twice as long as peduncle, 20-jointed; in ö longer than in Q, with 

 long sensory setae on flagellum. Antenna 2 much shorter and more slender 

 than antenna 1, ultimate Joint of peduncle shorter than penultimate; flagellum 

 rather longer than peduncle. Lower lip not easily dissected ont (see the greatly 

 differing flgures by Bonnier and Sars). Mandible with accessory plate, a 

 miuute fringe representing spine-row, and a smooth projection answering to 

 molar, long 3^ Joint of palp finely fuiTed. Maxiila 1, inner plate without 

 setae, outer probably with 6 spines, palp elongate, 1-jointed (in Boeck's figure 

 2-jointed). Gnathopod l, 6*^ Joint nearly linear, shorter than the longv 

 narrow 5*^^. Gnathopod 2, b^^ Joint narrowly cup-shaped, 6*^ subti-iangular^ 

 constricted at base, much widened distally, palm little "oblique, fringed with. 

 spinules, defined by a tooth. Peraeopods 1 — 5 very slender, 2<i Joint in peraeo- 

 pods 3 — 5 oblong oval, obliquely truncated at lower bind corner. Uropods 1 and 2, 

 rami narrow, acute, constricted towards the end and furnished with 2 spines 

 at the constriction. üropod 3, peduncle broad at base, produced at apex, 

 longer than ramus, of which the 1^* Joint is twice as long as 2*^ and carrie» 

 2 apical spines. Telson ending in an acute piece flanked on each side of 

 its base by an acute little tooth (not shown in Bonnier's figm'e). Colour 

 dark brown, spotted. L. 9 3 to about 6 mm, ö much less (Sars). 



North- Atlantic and North-Sea (Norway, depth 36 — 146 m; France; Great Britain). 



