AMPHIPODA. 21 



joint curved, oblong, almost as long and three times as wide as the next three ; third 

 and fifth subequal, fourth rather shorter ; dactylus slender, two-thirds of the length 

 of the preceding joint. 



Second perseopods ; Side-plates subtriangular, front margin straight, lower and 

 hind margins convex. The legs as in the first pair. 



Third p)erseopods ; First joint narrow, oblong, straight. 



Fourth and fifth perseopods alike ; first joint oval, deeper than wide, hind margin 

 smooth. 



The uropods are subequal in extent and sparsely spinous ; the peduncle of the 

 third pair is subequal to the first joint of the ramus, which is also subequal to the 

 second joint. 



Telson not reaching the end of the peduncle of the third uropods, narrowing 



rather abruptly to a point with two spines on each side before the middle and one 



beyond. 



Length, 3 mm. 



Thaumatelson.* 



Thaumatelson, A. 0. Walker, Ann. and Mag. Nat. Hist. XVIII. (1906), p. 15. 



General characters of Metopa. 



Palp of the first maxillae two-jointed. 



First gnathopods distinctly subchelate. 



Telson large, entire, oval and set in a vertical plane on its longer edge. 



T. herdmani. (PL 7, fig. 11.) 

 . herdmani, A. 0. "Walker, Ann. and Mag. Nat. Hist. XVIII. (1906), p. 15. 



W.Q., Oct., 1902; 8-net, Hut Point; from Sponges. One spec. W.Q., 13 Feb., 

 1904 ; D-net, Hut Point; one. 



Body as in Metopa : the fourth side-plate unusually large, covering the bases of 

 the last three pairs of perseopods. The last two pleon segments with a postero-dorsal 

 tooth. Segments of the urus coalesced. 



Antennae : subequal, longer than the head. 



Upper antennae : First joint longer than the second, which is rather shorter than 

 the third, and has the upper margin produced ; there is no appendage. Flagellum 

 shorter than the peduncle. 



Lower antennae : Peduncle subequal to that of the upper, second and third joints 

 subequal and together longer than the flagellum. 



Maxillipeds : Inner lobes reaching half-way up the narrow outer lobes, apparently 

 divided rather further down than in Metopa ; outer lobes, as in Proboloides, a mere 

 slight expansion of the inner margin of the basal joint, which is produced distally half 

 the length of the next joint, which, as well as the remaining joints of the palp, is short 



[Bectiua Thaumatotelson. — Ed.] 



