1240 THE VOYAGE OF H.M.S. CHALLENGER. 



with two small teeth breaking the line of denticles in the distal half; the long and 

 powerful finger has a sharp tip, which closes down between and beyond the large 

 palmar spine and a smaller one on the surface ; its inner edge is smooth. 



First Perseopods wanting, or only represented by the small joint, at the extremity of 

 which the branchial vesicles are attached. Branchial vesicles small and almost round, a 

 little narrowed at the point of attachment. Marsupial plates enormously larger than the 

 branchial vesicles, oval, the distal end the larger, the rim crenulate, fringed with setse. 



Second Perseopods in the same condition as the first. The branchial vesicles and 

 marsupial plates nearly as in the preceding segment, but in this the marsupial plates are 

 directed forwards instead of backwards ; they are, like the others, fringed with setse. 



Third Perseopods three-jointed, attached above the centre and at the broadest point 

 of the very narrow elongate segment ; the first joint attached to the distal border of a 

 small laminar projection which may be regarded as representing a side-plate, the joint 

 not twice as long as broad, distally widened ; the following joint more than twice as 

 long, armed with two or three setules ; the third joint as long as the first, slightly 

 tapering, with a setule at the apex, and one on either side a little way above it. There 

 is little or nothing to indicate what joints are homologically represented by these three ; 

 it may be supposed that the last represents the hand or fifth joint, and that the penulti- 

 mate represents the fourth, or the third and fourth combined. 



Fourth and Fifth Perasopiods. — Of these nothing was left but the stumps, but the 

 muscles running to them indicated that they are probably of the average size and 

 strength in jjroportion to the size of the animal. 



Uropods. — There was nothing about the pleon to indicate whether the uropods were 

 naturally or accidentally wanting. 



Length. — The specimen, in the position figured, measured without the antennas one- 

 seventh of an inch. Fully extended it would have been rather more. 



Locality. — Station 135c, off Nightingale Island, Tristan da Cunha, October 17, 1873 ; 

 depth, 110 fathoms. One specimen, female. 



Remark. — The specific name refers to the place of capture. 



Genus Protellopsis, n. gen. 



The First and Second Perseopods rudimentary, consisting of two joints. 



Uropods of the first pair reaching beyond the pleon, two-jointed, the second joint 

 comparatively long and narrow ; the second pair short, tapering. 



In other respects this genus is like Protella, Dana. 



In Mayer's arrangement of the Caprellidae this genus will stand immediately in front 

 of Protella. 



