80 GAMMARIDJl. 



as long as the head and first segment of the body; the 

 peduncle is longer than the flagellum, and the first joint 

 longer than the other two, the third being shorter than 

 the second. The flagellum consists of four articuli, the 

 first of which supports a brush of hairs, or rather one 

 or two short rows of auditory cilia long, delicate mem- 

 branous organisms, somewhat like transparent hairs, and 

 evidently intimately connected with the sensation of 

 hearing ; the secondary appendage is minute and slender, 

 consisting of two articuli only, one much longer than 

 the other. The first pair of legs are short, and have 

 the coxa but little developed ; the hand is tapering, and 

 furnished with two hairs near the base of the finger ; 

 the finger is slightly curved, terminating in a short nail, 

 and armed along the inferior margin with two minute 

 spinules. The second pair of legs are long and slender, 

 having the coxa deeper than that of the preceding pair ; 

 the wrist is nearly as long again as the hand, and has the 

 inferior margin thickly ciliated with long hairs ; the hand 

 is not broader than the wrist, and has the upper and 

 low^er margins nearly parallel, and thickly furnished with 

 long hairs ; the inferior angle is considerably produced, 

 so as to give to the organ a chelate character, although, 

 from its minute dimensions, one of feeble importance. 

 The finger is straight and tapering, having the apex 

 subapically furnished externally with a curved spine. 

 The third and fourth pairs of legs are subequal, toler- 

 ably robust, and alike, except in the form of their coxae, 

 which is much larger in the fourth than in the third pair, 

 and has a slight emargination, corresponding with the 

 margin of the anterior lobe of the coxa of the fifth pair 

 of legs. The three posterior pairs of legs are also of the 

 same length and form, tolerably strong, though not so 

 robust as the two preceding; their second joints are 



