72 BULLETIN 2 01, UNITED' STATES NATIONAL MUSEUM 



Both rami of third pair of male pleopods terminating in a robust, 

 spiniform, nearly straight, seemingly naked seta not longer than the 

 normal setae on the preceding joint and with the end obtuse. Each 

 ramus of fourth pair of pleopods (fig. 17, c) with peculiar setae; the 

 endopod terminates in two strong, naked, spiniform setae, the outer 

 seta almost straight, about as long as the sum of the three distal joints, 

 the inner seta distinctly shorter and less thick than the outer and 

 somewhat angularly bent before the middle; the exopod terminates 

 in two setae, one very short, while the other is nearly as long as the 

 long seta on the endopod, naked, robust, and, somewhat before the 

 middle, strongly bent in a very peculiar way. These setae are quite 

 similar in both uropods of the fourth pair. Finally the inner angle 

 of the penultimate joint has a nearly straight, naked, strong seta 

 scarcely as long as the long terminal seta. 



Uropods moderately slender (fig. 17, d). The exopod overreaches 

 conspicuously the endopod; its proximal joint is almost three times 

 as long as the distal, with 14 or 15 spines occupying somewhat more 

 than half its outer margin; distal joint not fully twice as long as 

 broad. Telson (fig. 17, d-e) somewhat less than three times as 

 long as broad, reaching a little beyond the articulation of the exopod 

 of the uropods; along a little more than the distal half each lateral 

 margin has an arrangement of spines nearly as in S. inomata, as 

 above 9 or 10 long spines are distributed so that proximally 4 or 3 

 shorter spines are found in each interval between 2 long spines, while 

 distally 3 or 2 (or only 1) are found in each interval. The terminal 

 margin of the telson has 3 somewhat small spines placed between the 

 single pair of very long and strong spines. 



Length of both sexes 9 mm. (Hansen, 1913b). 



Occurrence. — Three lots from La Jolla, Calif., collected by the 

 Scripps Institution, have been examined : Haul 432, October 3, 1916, 

 1 specimen; haul 2308, August 23, 1917, 2 specimens; haul 2425, 

 September 15, 1917, 1 specimen. 



Distribution. — This species is known only from the coast of Cali- 

 fornia, from which it has been recorded by Holmes (1900), Hansen 

 (1913b), and Tattersall (1932a). 



Remarks. — This species is distinguished from S. chierchiae, S. 

 roosevelti, and S. panamensis by the form of the third and fourth 

 pleopods of the male. Females of all these species are extremely alike 

 and very difficult to separate from one another. 



SIRIELLA ROOSEVELTI Tattersall 

 FlQUEES 18, 19 



Siriella roosevelti Tattersall, 1941, p. 2, figs. 1, 2. 



Description. — A /Siriella belonging to group II (Hansen, 1910) in 

 which the apex of the telson is armed with three small spines in the 



