EEPORT ON THE AMPHIPODA. 647 



rami long and slender, slightly spined, and only on the proximal part ; peduncles of the 

 second pair shorter than the rami ; outer ramus longer than the inner, both shorter than 

 those of the preceding pair; peduncles of the third pair much shorter than the rami, 

 with groups of spines at the apical points, the rami about equal in length to one another, 

 and to the longer of the second pair, the outer and under one forming a kind of neck at 

 the base, with its sides unarmed to below the centre, then with five small spines on the 

 inner, and four on the outer convex margin, ending with a decided nail ; the upper and 

 inner ramus broadest close to its base, and here on the inner margin with three spines, 

 then a long interval followed by three more leading to the apex ; on the outer margin 

 five unevenly spaced, three small ones at intervals on the surface. 



Telson reaching beyond the peduncles of the third uropods, much wider at the base 

 than below, cleft for two-fifths of its length, the whole cleft more or less dehiscent,, a 

 spine in the notch of each narrow apex ; several marginal spines, seemingly not quite 

 symmetrically placed. 



Length of the specimen from the rostrum to the back of the second pleon-segment, 

 in the position figured, three-fifths of an inch. 



Locality. — Station I., off Cape Finisterre, December 30, 1872; lat. 41" 58' N., 

 long. 9° 42' W.; depth, 1125 fathoms; bottom, blue mud. Dredged. The specimen 

 when it came into my hands was abeady broken into two portions. There was also the 

 front portion of a second specimen. 



Remark. — The specific name longimanns, long in the arm, refers to the unusual length 

 of the first gnathopods. In view of the peculiarities of the species, it is of interest to 

 note the great depth recorded for its habitat. 



Genus Onesimoides, n. gen. 



Mandibles with the palp set just over the dentate crown of the molar tubercle. 



First Maxillw with the inner plate carrying two unequal plumose setfe ; the second 

 joint of the palp not dilated, with more than six spine-teeth on the apical margin. 



Second Maxilla with the plates of nearly equal length, the outer rather the broader ; 

 the oblique apical margins, but not the inner ones, fringed. 



Maxillipeds with the outer plates reaching about as far as the apex of the second 

 joint of the palp, nodulous teeth numerous on the inner margin, one spine-tooth on the apex. 



U2yper Antennw with the first joint of the primary flagellum long, that of the 

 secondary equally long, spreading its wing (a thin laminar dilatation) over the other. 



Loiver Antennas with the third joint short, the fourth and fifth subequal in length. 



The side-plates of the perseon not projecting over the mouth-organs and base of lower 

 antennae. * 



