36 Mr. A. O. Walker on Amphipoda 



Uropod 1 : peduncle nearly twice as long as the subequal 

 rami. 



Uropod 2 : outer ramus shorter than inner, which is shorter 

 than the peduncle. 



Uropod 3 extending much beyond 2 ; rami subequal, longer 

 than the peduncle, spiniferous. 



Telson not much longer than the width at the base, cleft 

 two-thirds of its length, ends of divisions rounded, dehiscent. 



Characterized by the structure of the gnathopods. 



Fain. Talitridse. 



Genus Orchestia. 



Orchestia aucklandice, Sp. Bate, Cat. Amph. Crust. Brit. Mus. 

 p. 17, pi. i. a, 3. 



Enderby I., 19/3/04. Many males and females. 



Segments of the perajon smooth, without transverse ridges. 

 Hind epimeral margin of the third pleon-segment straight ; 

 obtusely serrate, with spinules between the teeth ; hind angle 

 right, a little produced backwards. 



Eyes round-oval, the longer diameter subequal to that of 

 the base of ant. 2. 



Ant. 1 not quite reaching the end of the penultimate joint 

 of the peduncle of ant. 2 ; flagellum in the male with 4 sub- 

 equal joints, in the female 3-jointed, the first the longest. 



Ant. 2 : last joint of peduncle the longest ; flagellum rather 

 longer than the peduncle, 18-jointed in both sexes. 



Gnathopod 1, <$ : side-plate narrowed and rounded below. 

 Wrist twice as long as the hand, both joints with a prominent 

 pellucid process ; that on the hand forming the palm and 

 furnished with a row of small spines. Finger reaching a little 

 beyond the process. In the female the limb is similar, but 

 slighter, and the pellucid processes much less prominent. 



Gnathopod 2, <$ : wrist short, not produced behind ; hand 

 almost as wide as long ; palm transverse, rather oblique, in 

 one specimen slightly convex in the middle, in another with 

 a distinct concavity near the base of the finger, spinulose and 

 defined by a strong tooth, hind margin subequal to the 

 palm. Finger nearly straight, extending beyond the tooth. 



Gnathopod 2, $ : wrist longer than the hand, a pellucid 

 process on both, that of the hand with a double row of spines 

 on the upper part and a single row at the base of the dactylus, 

 which does not reach the end of the process. 



Perseopod 1 longer than 2 ; in both the second joints are 

 about twice as wide as the fourth ; dactylus divided by a 

 false joint, the proximal part constricted. 



