1402 THE VOYAGE OF H.M.S. CHALLENGER. 



wider, especially just below the neck ; the second joint a little, and the third considerably, 

 larger than in the preceding pairs. The rest of the limb missing. 



Fourth Perseopods. — The first three joints as in the preceding pair, but the first a 

 little larger ; the fourth joint curved as in the other perseopods, and longer than the third 

 joint. The two other joints missing. 



Fifth Perseopods. — The first joint rather larger than in the preceding pair, the third 

 and fourth joints not so long, the fourth with the apical margin finely pectinate ; the 

 fifth joint curved, slender, tapering, longer than the fourth joint ; its margin pectinate ; 

 the finger missing. 



Pleopods. — Coupling spines moderately strong ; the cleft spine stout, the longer arm 

 denticulate within, and slightly widened apically beyond the dilatation of the other arm ; 

 the inner ramus with twelve joints, the outer with thirteen. 



Uropods. — Peduncles of the first pair much narrower, and only a little longer, than 

 those of the third, reaching back very little beyond those of the second, longer than the 

 narrow elongate rami ; the outer ramus rather shorter than the inner, pectinate on the 

 inner margin, the inner ramus reaching back not quite to the apex of the outer ramus of 

 the third uropods, pectinate along the outer margin and the lower part of the inner ; 

 near the bases these rami have little confronting emarginations ; peduncles of the second 

 pair intermediate in breadth, a little longer than the longer inner ramus ; the outer 

 ramus much the shorter and narrower, strongly pectinate on the inner margin, the inner 

 ramus pectinate on both margins, more closely on the outer somewhat sinuous margin ; 

 the peduncles of the third pair very broad, much longer than the rami, their pectinate 

 inner edges overlapping as soon as they meet just below the telson ; the broad distal 

 border also partially pectinate ; the outer ramus the longer, with straight outer margin, 

 the inner convex, pectinate ; the inner ramus broadly lanceolate, with both margins 

 pectinate. 



Telson scarcely so long as broad, rather more than a third of the length of the 

 peduncles of the third uropods, a bluntly pointed arch in outline. 



Length, from the front of the head to the back of the second pleon-segment, about one- 

 fifth of an inch. 



Locality. — Station 141, December 17, 1873; near the Cape of Good Hope; lat. 

 34° 41' S., long. 18° 36' E.; surface; surface temperature, 66°'5. One specimen, male. 



Remarks. — The specific name, derived from the Greek KpvirTw, I conceal, and SixktuXos, 

 a finger, refers to the retractile terminal joint in the gnathopods. It is of course likely 

 enough that this character, though first observed in the present species, may be common 

 to all the species of the genus, since in other respects they are separated only by small 

 distinctions. 



