REPORT ON THE AMPHIPODA. 1603 



Genus Streetsia, n. gen. 



Head not constricted at the base, much longer than the peraeon, the rostrum very 

 elongate and the eyes still more so. 



The Gnathopods complexly subchelate. 



The Second Perseopods longer than the First. 



The Fourth Perseopods with the hinder apex of the first joint acutely produced. 



The Fifth Perseopods with dilated first joint exceeding in length the other five 

 joints together ; the outstretched limb exceeding in length the first joint of the fourth 

 pair. 



The Uropods with the rami distinct from the peduncles ; the Third Uropods with 

 peduncles much longer than broad. 



The Telson produced far beyond the uropods, much longer than the coalesced fifth 

 and sixth segments of the pleon. 



The generic name is given in compliment to Dr. Streets who instituted the genera 

 Calamorhynchus and Leptocotis. 



Streetsia challengeri, n. sp. (PI. CCVIL). 



The Head is deeper than broad, but cylindrical in general appearance from the 

 base to the rostrum ; the latter is tapering, dorsally carinate, with serrate edges, and 

 though of great length, shorter than the proximal part of the head ; the peraeon is 

 dorsally rounded, the segments differing little from one another in length, with rather 

 deep side-plates, of which the upper boundary is distinctly marked, except in the case 

 of the seventh pair, where as so commonly the dividing line is limited to the hinder 

 part of the plate ; the pleon is more or less sharply carinate or dorsally angled, its 

 second and third segments having the postero -lateral angles acutely produced. 



Eyes of great length, occupying the whole sides of the head as far as the front 

 antennae, which are fixed just behind the base of the rostrum. 



Upper Antennas very small and slender, first joint of peduncle much longer than 

 the two following together, each of these being broader than long ; the first joint of the 

 flagellum tapering, as long as the first of the peduncle, carrying two groups of filaments 

 the second joint not half the length or breadth of the first, with an apical group of 

 filaments ; the third joint narrower and shorter than the second, tipped with setules 

 there are some setules or cilia on the peduncle and first joint of the flagellum. 



Lower Antennas attached near the base of the head within its channelled lower side 

 the gland-cone is conspicuous ; in addition to this, there is a triangular process of great 

 tenuity, and near to it a little round-headed process, one or both of which may be 

 antennary. 



