EEPORT ON THE AMPHIPODA. 605 



and hand, even when the two are tightly closed together. The spines on this limb, except 

 on the palm of the hand, are few and smalh In the female, the first joint is more 

 narrowed distally than in the male, the second joint is lobed on the front margin ; the 

 third and fourth joints much resemble in form the corresponding joints in the first 

 gnathopod of the male, but the hinder margin of the fourth joint is here thin and with- 

 out spines ; the hand, narrow at its origin, swells out to a postero-distal lobe beyond the 

 palm, without spines on the thin, curved hinder, or nearly straight front, margin ; 

 a row of spines along each side, a group close to the hinge of the feeble finger, 

 spinules along the palm, over which the finger closes tightly ; fur on the thin lobe which 

 projects beyond the palm. Wrist rather longer than hand and shorter than first joint. 



First Perieopods longer than second ; spines on both edges of all joints but 

 the second ; third joint longer than any but the first, fourth not much, some- 

 times not at aU, longer than fifth, both spinous ; finger short, with curved nail ; 

 branchial vesicle with a large basal, and a narrow terminal, lobe. 



Second Perseopods very similar to first, but dimensions smaller in regard to length, 

 the side-plate somewhat broader, the fourth and fifth joints equal in length ; the finger in 

 both sexes differing from that of the first perseopod in having its hinder margin sinuous. 

 There is a corresponding irregularity of outline in this margin in the second perjeopods of 

 Talitrus locusta, of Orchestia gammarellus, and in an exaggerated form in Tcdorchestia 

 tumida, G. M. Thomson ; but not, so far as I know, in Hycde or Hyalella. 



Third Per^opods very much shorter than the two following, though more than half 

 the length of the fifth pergeopod ; front lol^e of the side-plate nearly as deep as that of 

 the fourth segment ; branchial vesicle with a small basal, and a large oval terminal, 

 lobe ; first joint oval, with spines on front, and spinules on hinder, margin ; third, 

 fourth, and fifth joints spined on both edges, not difi"ering greatly in length, decreasing 

 successively in breadth ; finger small, with curved nail. 



Fourth Perieopods. — Hinder lobe of side-plate larger than the front one ; branchial 

 vesicle with a short narrow basal and a long narrow terminal lobe, the latter curving 

 first backwards and then downwards ; first joint a long oval, third and fourth joints 

 subequal, fifth rather longer and considerably thinner ; finger slender, longer than that 

 in the third perseopods. 



Fifth Perwopods. — Side-plate not bilobed, deeper behind than in front ; first joint 

 broader than that of the fourth perseopods, which in most respects these closely resemble, 

 but with the third, fourth, and fifth joints longer. 



Pleopods. — Peduncles long and slender, longer than the rami, wide apart at the base, 

 curving in towards one another, armed with a few small spines ; the joints of the rami 

 numbering from seven to eleven ; the setse very finely plumose ; I cannot perceive any 

 cleft spines on the long first joint of the inner ramus, such as are commonly found in 

 other families, nor even a single short one, such as occurs in Talitrus locusta; the 



