CRUSTACEA CASPIA. 367 



The 2 anterior pairs of pereiopoda (fig. 7) are very strongly built and 

 densely setiferoxis, with the meral joint large and expanded. 



The 3 posterior pairs of pereiopoda (figs. 8—10) are moderately slender, 

 and have their outer part edged with fascicles of slender bristles and scattered 

 spines. The basal joint of the antepenultimate pair (fig. 8) exhibits the usual 

 rounded quadrangular shape; that of the penultimate pair (fig. 9) is only 

 expanded in its proximal part, and gradually tapers distally. The last pair 

 (fig. 10) have the basal joint rather large and of a regularly oval form, 

 with the infero-posteal corner projecting below as a narrowly rounded 

 lappet. The posterior edge of this joint is, as in the 2 preceding pairs, 

 minutely serrate and fringed with short bristles. Of the outer joints in these 

 legs, the carpal one considerably exceeds the meral one in length, being 

 fully as long as the propodal joint. 



The 2 anterior pairs of uropoda (figs. 11, 12) have the rami rather 

 narrow and provided at the tip with several spines ; the outer ramus has also 

 one, and the inner, 2 lateral spines. 



The last pair of uropoda (fig. 1 3) do not differ much from those in the 

 2 preceding species, having the inner ramus very small, and the outer 

 densely fringed with partly ciliated setse. 



The telson (fig. 1 9) is about as long as it is broad, with the lateral 

 halves smooth except at the tip, which carries 3 slender spines. 



The adult male (fig. 14) is a little larger than the female, the length of 

 the body measuring about 13 mm. 



It does not differ much in its external appearance from the female, ex- 

 cept in being somewhat less tumid. 



In the specimen examined the accessory appendage of the superior 

 antennffi (fig. 15) was somewhat more fully developed and composed of 5 

 distinct articulations; otherwise the antennae exhibited the very same struct- 

 ure as in the female. 



The gnathopoda (figs. 16, 17) are,- as usual, much more powerfully 

 developed than in the latter, and of rather unequal size, the posterior ones 

 (fig. 17) being much the stronger, with the propodos very large, and of an 

 oblong oval form. In the anterior pair (fig. 16) the propodos is not nearly 

 so large, but of a more obpyriform shape. In both pairs the palm is rather 

 oblique, with the defining corner nearly obsolete, though armed with the 

 usual spines. As in most other male Gammari, there is also found a spine 

 about in the middle of the palm outside. 



The last pair of uropoda (fig. 1 8) are somewhat larger than in the 

 female, otherwise of a very similar structure. 



Occurrence. — Of this form solitary specimens were collected by Mr. 



*H3.-MaT. OTp. 347. 25 



