Orchestia 535 



Side-plates 2 — 4 quadrate, mucli larger and deeper than 1^* or ö*'^. 

 Eyes squarely rounded, black, less than the diaraeter apart. Antenna 1 

 reaching end of penultimate Joint of peduncle of antenna 2, flagellum 

 shorter than peduncle, 5-jointed. Antenna 2, about ^/g as long as body or 

 a little luore, ultiniate Joint of peduncle not much longer than penultimate, 

 flagellum subequal to peduncle, Iti-jointed in d, 12-jointed in Q . Gnathopod 1 

 in ö, 5*^ Joint not very much longer than 6*^ 4*^\ 5*** and ö^'^ joints pro- 

 duced behind into pellucid bosses, successively larger, narrow on joints 4 

 and 5, broad on Joint 6, which has a transverse palm, finger small, only 

 reaching end of true palm, not overlapping the boss. Gnathopod 2 in <5, 

 2*^ Joint with front margiu very slightly convex, not lobed, 3*^ Joint lobed, 

 5th yg^y gjuall, 6*'i large, ovate, widening slightly to the oblique, convex, 

 spinulose palm, which ends in a slight notch at the defining angle, finger 

 large, curved. Gnathopod 1 in Q , 4*^ and 5*^ joints not produced into 

 processes, 5^^ subapically widened, 6*^* narrowly oblong, with a scarcely 

 perceptible scabrous pellucid apical widening, which as well as the little 

 transverse palm is overlapped by the finger. Gnathopod 2 in 9 , expansion 

 of 2'* Joint wider above than below, 4*^ Joint squared at distal bind comer, 

 5*1^ with very convex free part of bind margin, 6^^ not much shorter, well 

 produced beyond the small longitudinal finger. The young from the 

 marsupium have gnathopods 1 and 2 almost exactly as in the mother. 

 Peraeopod 2, finger with sinuous inner margin. Peraeopods 3 — 5, 2^ Joint 

 broadly oval, successively larger, bind margin spinulose, 4^^ Joint moderately 

 Wide, üropods 1 and 2 not very spinöse, rami not much shorter than 

 peduncle, both rami with marginal spines. Uropod 3, ramus slender, nearly 

 as long as peduncle. Telson spinulose about apex. Colour light grey, 

 sometimes gi-eenish or brownish, always very pale. L. d 15 mm, 9 smaller. 



North-Pacific (San Francisco). Among the rejectamenta along high-watei- mark. 



8. O. serrulata Dana 1852 0. s., J.D.Dana in: P. Amer. Ac, v.2 p. 204 | 

 1853 & 55 0. s., J. D. Dana in: U. S. expl. Exp., v. 13n p. 870; t. 58 f. 7a— 1 (d), m— o 

 ($?) I 1893 0. s., A. DellaValle in: F. Fl. Neapel, v. 20 p.498 t. 57 f. 61, 62 i 1862 0. 

 aucklandiae -j- 0. s., Bäte, Cat. Amphip. Brit. Mus., p. 17 t. la f. 3; p. 31 t. 5 f.4 | 1886 

 O. a., G. M. Thomson & Chilton in: Tr. N. Zealand Inst., r. 18 p. 145 j 1893 O.a., 

 A. DellaValle in: F. FI. Neapel, u 20 p. 505 t. 57 f. 65 \ 1885 0. ornata, Filhol in: 

 Becu. Passage Venus, f. 3 11 Zool. p. 463 t. 53 f. 2. 



In (5 peraeon segment 1 encircled by a raised ridge or coiTugation, 

 Segments 2 — 7 (Thomson & Chilton: 2 — 5) similarly corrugated, except that the 

 front lidge is withdrawn from the front of the segment, and sometimes a 

 little broken; this character (not mentioued by Dana and Bäte) is wanting 

 in 9 or barely indicated. Side-plate 1 small, fi'ont margin straight, the 

 others or at least 2*^ — h^^ in d with encircling i'idge, 2<^ — 4*^ having a 

 conspicuous ridge down the centre. Pleon segment 3, postero-lateral corners 

 quadrate, in Q with a minutely produced point. Eyes subrotund, dark, in 

 both sexes wider apart than their diameter. Antenna 1 in d reaching 

 balf-Avay along penultimate Joint of peduncle of antenna 2, in 9 to the end 

 of it; 3 joints of peduncle subequal, flagellum 6- or 7-jointed. Antenna 2 

 smooth, much larger in d than in o , peduncle angular in section, ultimate 

 Joint not greatly longer than penultimate, both long in d ; flagellum 17- or 

 18-jointed, shorter than peduncle in d, longer in 9. Gnathopod 1 in d, 

 5*^ Joint strongly produced into subapical tubercle, 6*^' shorter, but with 

 apical process broadly produced, so that the finger does not reach the end 



