384 MRS. E. W. SEXTON ON A [Apr. 28, 



Male. The proportions of the joints to each other are the same 

 as ill the female, but all are longer, the 2ncl, for example, 

 equalling the 2nd and 3rd of the female taken together. 



Setce practically the same as in the female. The 5th has three 

 pairs and two single spines ; the 6th one pair and five single, 

 with the distal half of the margin dentate ; the claw has four 

 denticles. 



Fifth Per^opod. — Female (PI. XYII. figs. 2 & 3). 2nd joint 

 long, a little concave anteriorly with an oblique groove mid- 

 way along the margin in which the branchial vesicle rests, less 

 expanded posteriorly than the preceding pereeopod ; 3rd small ; 

 4th as long as the 2nd and longer and broader than the 5th or 

 6tli ; 5th and 6th subequal ; 7th half the length of the 6th. 



Setce. — This peraeopod is armed anteriorly with a formidable 

 array of spines. The 2nd joint has the one minute setule 

 posteriorly ; one large spine on the anterior angle. The 3rd has one 

 large spine. The 4th carries six on the maigin and one at the 

 angle posteriorl}'^ ; one pair and six single on the margin and 

 three at the angle anteriorly. The 5th has three of the sensory 

 setules and one spine posteriorly ; the anterior margin dentate 

 with six pairs and one single spine inset and three at the angle 

 (fig. 3). The anterior margin of the 6th is also dentate with 

 one pair and five single spines inset ; fovir sensory setules poste- 

 riorly. The claw is provided with five denticles (tseven in another 

 specimen). 



Male. Proportions of the joints to each othei' as in the female, 

 but all longer. 



Setce. — Nine spines on the anterior margin of the 4th joint ; 

 three pairs and four single spines on the 6th, the rest as in the 

 female ; five denticles on the claw (three on the Mediterranean 

 specimen). 



Pleopods (PI. XVII. figs. 4, 5, 6, 7).- -The peduncles are 

 large and stout, with two little coupling spines (fig. 5). The 

 rami are about twice the length of the peduncles. The outer 

 ramus has 22 articulations, the long first joint carrying on both 

 margins proximally a tuft of fine hyaline sensory hairs with 

 flattened tips ; the inner ramus is provided with similar tufts 

 and has six cleft spines (fig. 7) on the inner side of the first 

 joint, with an uncinate plumose seta (fig. 6) on each of the 

 following thirteen joints on the inner side. 



Uropods (PI. XYII. figs. 8, 9, 10). — The peduncles are large 

 and stout; that of the 1st uropod longer than the rami; that 

 of the 2nd subequal to the rami in length ; while in the 3rd the 

 rami are slightly longer than the peduncle. The apices of the 

 1st uropods reach considerably beyond the peduncles of the 3rd; 

 those of the 2nd and 3rd are almost on a level (fig. 8). The 

 rami of the 1st and 2nd pairs are greatly curved. 



The first tirojjod has seven small spines on the inner margin 

 of the peduncle which is serrated for half its length, with small 

 serrations along the distal margin also. The outer ramus 



