ISOPODS OF NORTH AMERICA. 441 



flattened in front, and produced into a moderately large acute process; 

 the front margin outside the base of each antennula produced into a 

 rather large process, which is broad at the base, while its distal part is 

 shaped as a narrow, acute hook, curved somewhat inward. Eyes large, 

 oblong, very oblique; the outer margin extremely convex, the inner 

 very concave; their posterior part overlaps the lateral margin of the 

 head itself. 



"Antennulae have the second joint of the peduncle moderately 

 robust and somewhat shorter than the third; flagellum 9- jointed, as 

 long as the sum of the two proximal joints of the peduncle. 



"Antennae have the basal joint, seen from above, ' distally cut off 

 transversely, its outer angle acute, but not produced into &ny process. 



" First thoracic legs rather short. Third joint distally widened, but 

 without process; fourth joint with the upper part nearly from the base 

 strongly expanded, compressed, and distally produced into a process of 

 moderate length and breadth; fifth joint similarly expanded and dis- 

 tally produced into a long slender process. Hand a little more than 

 twice as long as deep; upper margin rather feebly convex, with a few 

 setse; lower margin straight, only half as long as the upper, with 

 numerous very long hairs; distal end as long as the lower margin; 

 palmar edge very oblique, a little sinuate, furnished with six very stiff 

 setae, proportionate!}" long and increasing in length downward, pecti- 

 nate along their upper margin, and at the end of the edge a moder- 

 ately robust very long spine pectinate as the seta?; the angle between 

 palmar edge and lower margin measures about 130. Seventh joint 

 with its claw claw-shaped, reaching a little beyond the lower end of 

 the palmar edge; the joint is adorned below with serrated spines and 

 finely curved seta? as in S. mediterranwm, but the spines are less 

 numerous, only about ten. 



"Abdominal shield is somewhat broader than long; each lateral 

 margin is adorned with five small nearly spiniform processes, increas- 

 ing in size backward and placed at regular intervals, the last of these 

 processes being that at the usual notch. Posterior margin is rather 

 evenly but moderately curved. 



" Uropoda wanting. 



"Length of the single adult female, 6 mm. v HANSEN." 



STENETRIUM OCCIDENTALE Hansen. 



Stenetrium occidentale HANSEN, Proc. Zool. Soc. London, 1905, II, Pt. 2, pp. 324- 

 325, pi. xx, figs. 2a-2n. 



.Locality. St. Thomas, West Indies. 



" Head shaped as in S. antillense; its upper surface (the frontal 

 plate excluded) is considerably less than twice as broad as long; the 

 lateral part, seen from above, is feebly expanded and produced into a 



Proc. Zool. Soc. London, 1905, II, Pt. 2, pp. 323-324. 



