44 



with both rami equal and terminating in feathered setae. Fourth pair of male pleopods with 

 the endopod conspicuously longer than the normal exopod and terminating in four modified 

 setae (fig. 30)-, terminal joint with its two sets only moderately strong, naked and distinctly 

 curved, and the outer setae a little more than half as long again as the inner, but conspicuously 

 shorter than the sum of the three distal joints; penultimate joint considerably elongated and 

 somevvhat slender, with its outer terminal seta naked and twice as long as the inner seta of the 

 terminal joint, while its inner naked seta is somewhat shorter, about as long as the outer seta 

 of the terminal joint. Uropods in both sexes nearly as in the male S. distinguenda ; the exopod 

 conspicuously longer than the endopod, with 10 — 12 spines on the outer margin of the proximal 

 joint (fig. 3 ö), while the distal joint is a little less narrow than in the two preceding species, 

 being about two and one-third times as long as broad. The telson about as in 5. distinguenda. 



Length 10.5 — 12.4 mm. 



Remarks. - The male of this species is very similar to S. cequircmis in the structure 

 of the endopod of fourth pair of male pleopods, but it is larger and easily separated from 

 S. cequiremis by the difference in the length of the rami of the uropods. The male is easily 

 separated from S. distiug7ienda by the great differences in the modified setae of fourth pair of 

 pleopods, but the female is extremely similar to the females of 5". anomala and 5. distinguenda^ 

 the only differences being, that the frontal plate is scarcely or not acuminated and the distal 

 joint of the uropods scarcely as slender as in these two species. 



Group ./. — End of telson without small spines, but with three (four) pairs of very long 

 spines. Proximal joint of the endopod of the uropods serrated nearly to the base, but with only 

 a few spines placed with long intervals; it is less than twice as long as the distal joint which 

 is nearly three times as long as broad. Proximal widened part of the telson with two pairs of 

 marginal spines ; spines along the distal half of the lateral margins of a peculiar irregular aspect 

 and most of them small. Male unknown. 



24. Siriella duóia n. sp. PI. V, figs. 4^7 — <\e. 



Stat. 142. August 5/7. Anchorage off Laiwui, coast of Obi Major. 23 m. Plankton. 1 specimen, 

 an adult female. 



Description of the Female. — Body slender. Frontal plate somewhat produced, 

 forming a rather low triangle with the anterior oblique margins straight and the end blunt 

 (fig. 4«). Eyes large, black; the eye-stalks considerably longer in proportion to their breadth 

 than in the preceding forms, the distal joint being about as long as broad tovvards the base. 

 Antennal squama slightly more than three times as long as broad; the terminal lobe unusually 

 long, a little longer than broad. Gnathopods (fig. \b) and first pair of thoracic legs (fig. \c) 

 somewhat slender, the last pair slightly longer than, but scarcely as strong as, the gnathopods; 

 the other thoracic legs wanting in the specimen. 



Uropods (fig. \d) slender; the exopod considerably longer than the endopod, its proximal 

 joint serrated from near the base to the end, with a strong spine near the end, a second spine 



