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



of the extremity of the appendage ; the peduncle terminates in a flagellum that equals in 

 length the entire animal from the orbit to the extremity of the telson. 



The mandible (fig. 2d) has the psalisiform process developed as a small, pointed 

 organ, of but little apparent utility ; the molar process is strong, broad, and square, and 

 the synaphipod is three-jointed, the first or basal joint being the shortest. 



The siagnopoda bear a general resemblance to those of Hippolyte, as also does the 

 first pair of gnathopoda. The second pair of gnathopoda is subpediform as in Hippolyte, 

 but does not carry a basecphysis. 



The first pair of pereiopoda is short, robust, and chelate, having the carpos nearly as 

 long and stout as the propodos ; the propodos is subcylindrical, about twice the length of 

 the dactylos. The second pair is long, slender, terminates in a minute chela, and has the 

 carpos long and multiarticulate. The posterior three pairs are moderately long and robust 

 and terminate in a sharp pointed dactylos, armed on the inner margin with three fine teeth. 



The pleopoda have the peduncle posteriorly longitudinally marginate and distally 

 produced to a point, terminating in two subfoliaceous rami fringed with hairs. The 

 first pair in the male has the outer branch more rigid than in the other pairs, and the 

 inner is shorter. 



The rhipidura has the outer plates subequal with the inner, and armed on the outer 

 margin with a strong ridge, terminating in a sharp tooth that coincides with the outer 

 extremity of the diaeresis. 



Many specimens of this species were taken by the dredge in the Southern Indian 

 Ocean. They vary in size from 1 to 3 inches, and none of them were carrying ova. 

 The females appear to differ from the males only in the varying length of the branches of 

 the first pair of pleopoda. 



Tozeuma serratum, A. Milne-Edwards, 1 which was taken at a depth of 40 fathoms 

 off Barbados, belongs, I think, to this genus. It resembles Chorismus tuberculatus in 

 general aspect, in the ornamentation of the rostrum and dorsal crest, and in having the 

 first pair of antennae and the second pair of pereiopoda short. It is excluded from 

 Stimpson's genus Tozeuma by having the carpos of the second pair of pereiopoda multi- 

 articulate instead of triarticulate, as described by that author. 



Merhippolyte, n. gen. 



In general appearance this genus resembles Spirontocaris, but carries no teeth above 

 the orbit. The frontal margin has an antennal tooth, and the fronto-lateral angle is 

 produced to a point. 



The ophthalmopoda are pyriform, the ophthalmus globular and furnished with a 

 distinct ocellus. 



1 Recueil de Figures de Crustaces nouveaux ou peu connus, aviil 3 883. 



