REPORT ON THE AMPHIPODA. 1349 



pectinate, with rounded hinder angle ; the wrist not longer than the hand, the inner or 

 front margin of the produced hinder apex pectinate ; the serrate distal appendages of 

 the hand (dactyloptera) nearly reaching to the narrow bent nail of the finger. 



Second Gfnathopods very similar to the first but longer, the produced apex of the 

 wrist decidedly less than half the length of the hand. 



First Perasopods. — First joint armed with two or three setules, one of which is on 

 the minute subapical tooth of the hind margin ; the third joint is more than half the 

 length of the fourth, aud the fourth is two-thirds the length of the somewhat curved 

 fifth ; all these, and the second to some extent also, have the hind margin fringed with 

 hail's ; apically the fifth joint is produced into an almost straight pointed process on one 

 side of the minute bent finger. 



Second Perieopods. — The branchial vesicles slender, much shorter than the first joint. 

 The marsupial plates much larger than the branchial vesicles. The limb similar to that 

 of the preceding pair, but with all the joints longer and stouter, the first joint having a 

 little projection of the hind margin closer to the actual apex and not produced into a 

 tooth. 



Third Perseopods. — Branchial vesicles longer than the preceding pair. The limb 

 shorter than in the preceding pair. The first joint as long as in the second perseopods and 

 a little stouter, distally channelled behind, the hind margin on the outer surface produced 

 into a rather long tooth, which, however, scarcely descends below the front part of the 

 distal margin ; the rather broad second joint, which is channelled behind, has the front 

 margin produced into a small apical tooth ; the broader and longer third joint has two 

 setules on the very convex hind margin and two on the rather shorter nearly straight 

 front ; the massive fourth joint, widening at once from the point of attachment, has a 

 distal breadth more than three-quarters of the length, the hind margin at first very convex, 

 then nearly straight, the front margin slightly sinuous, produced apically into a short 

 curved tooth ; between this latter and a second smaller tooth of the distal margin there is 

 a cavity occupying more than a third of that margin, and armed with one setule ; a much 

 smaller cavity follows the second tooth, and this is succeeded by a triangular setuliferous 

 margin leading to the hinge of the finger ; over this distal border and projecting consider- 

 ably beyond it closes the finger-like fifth joint, equalling the fourth in length, with convex 

 outer margin and sinuous setuliferous inner or front margin, the convex portion of 

 which partially occupies the larger cavity of the preceding joint ; the finger is minute, 

 affixed at the narrow apex of the fifth joint. The form of the fourth joint agrees very 

 nearly with that which Claus figures for the male of Phronima sedentaria, except that 

 there the triangular piece of the distal margin near the hinge is subdivided into five little 

 teeth. 



Fourth Perieopods. — Branchial vesicles longer than the preceding pair, about as long 

 as the first joint but not nearly so broad. The first joint oval, with the gland-cells 



