144 GAMMARIDJ5. 



second and third joints are small; the flagellum consists 

 of seven articuli, and is rather longer than the peduncle. 

 The secondary appendage is about half the length of the 

 primary. The inferior antennae are slightly longer than 

 the superior ; the peduncle extends beyond the peduncle 

 of the superior ; the flagellum has the first four or five 

 articuli very short, the remainder irregularly increasing 

 in length. The foot-jaws nearly resemble true legs, and 

 terminate in a short sharp-pointed finger, retaining the 

 characteristic of their true nature only in two small scale- 

 like processes, springing from the second and third joints, 

 the joints are all of the same length. The large squa- 

 mose coxae of the four anterior pairs of legs are deeper 

 than their respective segments, the three anterior having 

 the posterior half of the inferior margin furnished with 

 five hairs, the hindmost of which is short. The coxae of 

 the three posterior pairs of legs are much shorter than 

 those of the preceding pairs. The first two pairs of 

 legs are subequal, tolerably strong, each having a hand 

 of nearly similar form ; that of the first pair is almost 

 quadrate, the margins nearly parallel, the palm is some- 

 what oblique, slightly convex, and slightly serrated, de- 

 fined by a short sharp tooth. Those of the second pair 

 are rather longer, and have the palm defined by a longer 

 and sharper denticle ; the fingers are sharp and slightly 

 curved. The next two pairs of legs are slender; the 

 fifth pair are tolerably robust, but not very long, having 

 the second joint considerably dilated posteriorly; the 

 sixth pair are longer than the fifth, very similar in form. 

 The seventh also resemble them, but are very much 

 shorter, the third and following joints being scarcely as 

 long as the largely-dilated second joint ; all the legs after 

 the first two have the finger very short. The three pairs 

 of natatory appendages are not very long, and are pro- 



