1548 THE VOYAGE OF H.M.S. CHALLENGER. 



from below, showing the antennae and mouth organs in situ ; the appearance of these in 

 a lateral view is given in the adjacent figure on the right ; below the figure mxp. is a 

 figure of the dilated stomach. 



First Gnathopods. — Side-plates sharply produced forwards. First joint curiously 

 twisted, narrow at the base, then greatly widened by the backward bend of the hind 

 margin, this margin then crossing the surface to the lower apex of the sinuous front 

 margin, the joint at the elbow being much wider than above or below it ; as in the j)re- 

 ceding specimen the second and third joints have some small spines on the hind margin ; 

 in this genus, as in many genera of the Hyperina, the third joint, having assumed the 

 form of a small wrist, is an exception to Spence Bate's rule, that in the gnathopods the 

 third joint always underrides the fourth ; the much dilated wrist has the broadly 

 produced front apex scarcely perceptibly pectinate ; the chela-forming process has on 

 the front or inner margin five teeth besides denticles, and on the hinder or outer margin 

 eight teeth and a few denticles ; the apical tooth is additional ; the hind margin of 

 the hand has nine teeth. 



Second Gnathopods.- — The first joint a little curved, the lower part of the front 

 channelled ; the front apex of the wrist not produced downwards, nor nearly so large as 

 in the first pair, finely pectinate, and carrying three or four little teeth, the chela-process 

 with seven teeth on the front margin, one of them being an accessory denticle to the 

 apical tooth ; the hind margin is pectinate for some distance from the base, and then 

 divided into four or five teeth ; the hind margin of the hand has eight teeth. 



Third Perseopods with the first joint a long oval, not quite twice as long as broad. 



Fourth Peneopods. — The first joint not at all longer than the first joint of the 

 preceding pair, but with the upper part very much wider, the lower margin in front of 

 the second joint scarcely or not produced below that joint ; the third, fourth, and fifth 

 joints with the front margin closely pectinate with large and small teeth ; the finger 

 having some small decurrent teeth along much of the inner margin. 



Fifth Perseopods. — The first joint much longer than wide, widest at the centre, the 

 width there exceeding the length of all the other joints together, those joints being 

 nearly as in specimen A. 



Pleopods. — The rami with fourteen or fifteen joints. 



Uropods very similar to those of the species just named. 



Telson as long as the third uropods, its breadth rather more than two-thirds of its 

 iength, more rounded apically than in specimen A. 



Length, in the bent position figured, two-fifths of an inch. 



Locality. — July 1875, North Pacific, between Japan and Honolulu; lat. 35° N.; 

 surface. Male specimen. 



Remarks. — A female specimen from the same locality has the first joint of the first 



