210 THE VOYAGE OF H.M.S. CHALLENGER. 



sliorter aud broader, only three times as long as broad, and of a somewhat rhomboidal 

 form, the apex being very obliquely truncate, with the inner corner strongly projecting, 

 and the denticle of the outer farther removed from the apex than is the case in 

 Siriella thompsoni. 



The legs are somewhat more robust, and have the propodal joint distinctly 

 subdivided into two articulations, the proximal being the shorter. The terminal claw, 

 moreover, is comparatively much more elongate. 



The telson (see fig. 27) is somewhat less slender than in the preceding species, 

 and has a decidedly linguiform shape, the apex being evenly rounded, not truncate. The 

 lateral edges are coarsely denticulate along their outer part, and the posterior pair of 

 denticles, issuing from the apex, are considerably longer than the rest. Between the 

 latter projects (see fig. 28) a small tridentate plate bearing two delicate diverging 

 bristles. 



The uropoda (see fig. 27) have the inner plate but very slightly longer than the outer, 

 and the auditory apparatus well developed. The outer plate has a smaller number of 

 spines at the exterior edge than in Siriella thompsoni, not more than two or tlu-ee being 

 frec[uently found. 



The arrangement of the pigmentary spots on the body is very similar to that in the 

 preceding species. But in this form occurs in addition a richly arborescent pigmentary 

 deposit on the basal part of the telson, as also on the ocular pedicles. 



Habitat. — Of this species, too, all the specimens in the collection were taken at the 

 surface of the sea, but somewhat sparingly, not more than one or two specimens being 

 taken as a rule in each place. The following is a list of the localities, with dates 

 appended : — 



The specimens examined by Dana were collected in the Pacific at three difi"erent 

 localities. 



Diatrihution. — To judge from the above stated localities, the distribution of the 

 present species would seem to be more restricted than is that of the preceding 

 form, it being exclusively met with in the Pacific Ocean and the seas of the Indian 

 Archipelago. 



