182 Dr. W. T. Caiman on new 



revision o£ the Gammaridea (' Das Tierreich,' Lief. 21, 1906, 

 p. 693). Some modification of the definitions given in that 

 work is necessary to admit the species described below. In 

 the definition of the family the words " Pleopods with 

 peduncle produced on the inner side " must be omitted. In 

 that of the genus " pleon segments 1 and 2 very short " and 

 " antenna 1 short " are no longer applicable ; the inner plate 

 of " maxilla 1 " may have nine setae and that of " maxilla 2 " 

 four setse on the inner margin; the "2nd joint little ex- 

 panded " does apply to the fifth peraeopods, and the inner 

 ramus of " uropod 3 " is absent in the new species. 



Chelura insula, sp. n. (PI. V. figs. 1-6.) 



Description of ovigerous female. — Length of body about 

 fi mm. ; greatest breadth about - 9 mm. 



General form of the body (fig. 1) more slender than in 

 C. terebrans, the dorsal surface with more numerous scattered 

 setse. Third pleon somite with three subequal tubercles on 

 its hind margin (fig. 2) ; the following segment (fourth to 

 sixth somites fused) about one-fiflh of total length of body. 

 Fifth and sixth side-plates with very small anterior lobe. 



Antennule (fig. 1) nearly two-fifths as long as body; fla- 

 gellum sparsely setose, little longer than last segment of 

 peduncle, with five segments ; accessory flagellum unseg- 

 mented, about half as long as first segment of flagellum. 



Antenna (fig. 1) about half as long as body; last segment 

 of peduncle subequal to penultimate and longer than ante- 

 penultimate, less densely setose than the flagellum ; flagellum 

 more than three times as long as broad, with indications of 

 segmentation becoming more distinct distally. 



Mouth-parts closely resembling those of G. terebrans, but 

 the mandibular palp is longer and has a relatively larger 

 proximal segment with a group of seta? at its distal end ; 

 inner plate of maxillula broader, with about nine setae ; 

 inner plate of maxilla with four setae below the longer one 

 which marks the distal limit of the inner edge. 



First gnathopods (fig. 3) very large, about two-fifths of 

 length of body ; breadth of propodus (palm) two-thirds of its 

 length, palmar edge sloping backwards to about half the 

 length of the propodus, irregularly dentate and defined by a 

 strong tooth ; dactylus stout, longer than the palmar edge. 

 Second gnathopods (fig. 4) slender ; carpus about as long as 

 propodus, the latter about four times as long as broad, nar- 

 rowing distally, minutely subchelate; all the segments 

 carrying numerous very long setae. Peraeopods (fig. 1) with 



