762 THE VOYAGE OF H.M.S, CHALLENGER. 



Telson long oval, not nearly reacliing the end of the peduncles of the third uropods, 

 flattened at the top, with a rounded point at the apex, with three spines on each margin, 

 the larorest and lowest of which is a little below the centre. 



o 



Length. — The specimen, in the position figured, measured in a straight line from the 

 front of the head to the back of the third pleon-segment, one-fifth of an inch. 



Locality. — Station 313, off Cape Virgins, Patagonia, January 20, 1876; lat. 52° 20' 

 S., long. 67° 39' W.; depth, 55 fathoms; bottom, sand; bottom temperature 47°"8. 

 One specimen, female. Trawled. 



Station 135c, ofi" Nightingale Island, Tristan da Cunha, October 17, 1873 ; depth, 

 100-150 fathoms. One specimen, female, smaller than that from Station 313. 



Remarlcs. — The careful comparison of the specimen from Station 313, point by 

 point, with Aletopa inagellanica, from the same station, makes it clear that, in spite of 

 some general resemblance, the two forms are specifically distinct. 



The specific name alludes to the palm-margin of the second gnathopods. 



Metopa parallelocJieir, n. sp. (PL XLIIL). 



Rostrum obsolete, lateral lobes of the head not very prominent ; postero-lateral 

 angles of the first three pleon-segments not acutely produced. 



LJi/es round, rather high up on the sides of the head. 



Upper Anteimie, — First joint longer and thicker than the second; third joint about 

 half the length of the second ; flagellum of eight joints, together shorter than the 

 peduncle, but one or two joints are probably missing ; accessory flagellum rudimentary, 

 very thin, two-jointed, tipped with setules, scarcely half as long as the first joint of the 

 primary flagellum. 



Lower Antenna longer than the upper. First two joints very short, the third longer ; 

 the fourth and fifth elongate, the fifth more so than the fourth, both with several 

 marginal setules ; the flagellum of nine joints, together scarcely as long as the fifth joint 

 of the flagellum, the first joint as long as the four following and much broader, its width 

 irregular, one margin serrate and carrying setules at four points. 



Upper Lip with the distal margin unsymmetrically bilobed. 



Mandibles, so far as observed, agreeing with those of Metopa crenatipalmata. 



Lower Lip. — The mandibular processes rather narrow. 



First and Second Maxilla not materially difiierent from those of the two preceding 

 species. 



Maxillii^eds like those of Metopa crenatipalmata, but with the inner plates shorter, 

 and with two setse close together on the apex of the rudimentary outer plate. 



First Gnathopods. — Side-plates small, almost concealed. First joint shorter than the 



