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



Telson shaped like that of Atyloides australis, but not longer than the peduncle of 

 the third uropods. 



Length. — The specimen, in the position figured, exclusive of the antenna?, measured 

 something less than one-fifth of an inch. 



Locality. — From the screw of the Challenger on December 18, 1873, a date which 

 corresponds with Station 142, off Cape Agulhas ; lat. 35° 4' S., long. 18° 37' E. 



Remark. — The specific name refers to the great likeness between this species and 

 A tyloides australis. 



Atyloides serraticauda, n. sp. (PL LXXVIII.). 



Rostrum minute ; first and second segments of the pleon with the postero-lateral 

 angles forming a minute tooth ; the second having about the middle of the so-called 

 epimera or immovable side-plates a row of eight spines, the largest lowest, with an anterior 

 row of four ; third segment of the pleon having the postero-lateral angle toothed, with a 

 rather larger tooth on the hind margin immediately above that at the angle ; the lower 

 margin having in its anterior half several submarginal spines singly and in groups. 

 Surface hairy. 



Lyes large, reniform, retaining colour in spirits, situated near the lateral lobes of 

 the head, and with only a narrow space between them at the top of it. 



Upper Antennse. — First joint more than twice as long as broad, longer than the 

 second and third together, its upper margin longer than the lower; second joint twice 

 the length of the third joint, which is small, not twice as long as broad; flagellum with 

 sixty-two joints remaining in the specimen examined, about five times as long as the 

 peduncle; the accessory flagellum rudimentary, consisting of one conical joint, about half 

 the length of the first joint of the primary flagellum, tipped with two or three small setae, 

 and having a small hair on the margin. 



Lower Antennse. — First three joints short, the first very little expanded, the 

 gland-cone decurrent, and, like the first and third joints, with short setae at the a]3ex ; 

 the fourth joint equal in length to the preceding three united, a little shorter than the 

 fifth, its upper margin produced in a small rounded projection ; the fifth joint having 

 like the fourth several groups of stiff setae on the under or inner side ; the flagellum 

 of thirty-four joints, of which the first equals between three and four of those which 

 follow it. 



Upper Lip. — The outer plate rather narrowly rounded at the distal end, the 

 central part of this margin closely set with microscopic teeth or spinules. 



Mandibles. — Cutting plate with seven or eight teeth ; secondary plate on left 

 mandible widened distally, cut into five teeth ; on the right mandible slight in structure, 



