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



third pair not much longer than the proximal division of the ramus, which carries 

 three marginal spines, and is itself not much larger than the second joint or nail ; 

 these uropods reach back a little beyond the telson, but not so far as either the second 

 or third pairs. 



Telson long, more than twice as long as broad, with an acute apex. 



Length. — The specimen, in the position figured, measured, from the front of the head 

 to the apex of the first uropods, less than one-fifth of an inch. 



Locality. — Station 149h, Cumberland Bay, Kergueleu, January 29, 1874; depth, 

 1 27 fathoms ; bottom, volcanic mud. Three specimens. 



Remarks. — The specimen described is a female. 



The species is very like Metopa nasuta, Boeck, which also has the large beak or nose 

 formed by the first joint of the upper antennae. Hence the specific name is a hybrid, to 

 express "of the lineage of nasuta." In Boeck's species, the beak of the upper antennae 

 does not quite reach the end of the second joint; the maxillipeds have the second joint 

 only as long as the two following joints, and the finger much shorter than the preceding 

 joint ; the first gnathopods have the hand narrow and not subchelate ; the second 

 gnathopods and the perseopods have not the same proportions as in the Challenger 

 species ; for instance, in Metopa nasuta the fifth joint of the fifth perseopods is described 

 as equalling in length the two preceding joints. 



Metopa magellanica, n. sp. (PL XLI.). 



Rostrum and lateral angles of the head inconspicuous ; first three segments of the 

 pleon with the points of the postero-lateral angles not produced ; the fourth segment 

 with a slight dorsal depression. 



Eyes round. 



Upper Antennae. — First joint thicker but not much longer than the second ; the 

 third rather more than half as long as the second ; the flagellum slender, tapering, 

 rather longer than the peduncle, consisting of thirteen joints ; there is a rudimentary 

 two-jointed secondary flagellum, but it must not be supposed that this is as obvious in 

 the specimen as it appears in the figure, where it is isolated from the numerous mai'kings 

 that are visible on and beneath the surface. 



Lower Antennas longer than the upper; first three joints very short, gland-cone very 

 small ; fourth joint long and slender, rather thicker and a little shorter than the fifth ; 

 the flagellum of eight joints rather shorter than the fifth joint of the peduncle ; but 

 perhaps one or two joints of the flagellum may be missing. 



Ujjper Lip with the distal margin unsymmetrically bilobed. 



Mandibles. — The cutting edge rather broad and angular, divided into ten denticles. 



