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



Atyloides australis (Miers) (Pis. LXXV., LXXVL). 



1875. Paramcera australis, Miers, Ann, and Mag. Nat. Hist,, ser. 4, vol. xvi. p. 75. 



1875. Atylus australis, Miers, Ann. and Mag. Nat. Hist., ser. 4, vol. xvi. p. 117. 



1876. „ „ S. I. Smith, Bull. U.S. Nat. Mus., vol. iii. p. 61. 



1879. „ ,, Miers, Zool. of Kerguelen Island, Trans. Venus Exped., ZooL, p. 9, 



pi. xi, 

 1879. ,, „ Studer, Arch. f. Naturgesch., Jahrg. xliv. Bd. i. p. 126. 



1880 1. ,, megalophthalmus, Haswell, Linn. Soe, N.S.W., vol. v. p. 102, pi. vi. fig. 4. 

 1882. „ „ Haswell, Catalogue of the Australian Crustacea, p. 244. 



Rostrum minute ; animal rather compressed ; posterolateral angles of the third 

 pleon-segment rounded, the lower part of the hind margin a little serrate, the lower 

 border of this and the preceding segment having several submarginal spines. 



Eyes close to the little-developed lateral lobes of the head, rather large, reniform, 

 dark in the specimens preserved in spirits. A few of the ocelli, as seen from the inner 

 side, are figured on PL LXXV., fig. oc. 



Upper Antenna not long, the peduncle shorter than the flagellum, the first joint in 

 large specimens twice as long as broad, equal in length to the next two united, in small 

 specimens longer than broad, longer than the next two united ; the third joint about half 

 the length of the second, all three with groups of setae on the lower side, which in the 

 larger specimens is rough with short spiny or scaly hairs ; flagellum in a large specimen 

 of fifty-five joints, in a small specimen of twenty-one joints, tapering, the earlier joints 

 broader than long, every other widening at the lower apex, and there armed with a group 

 of setae, and in large specimens two or three cylinders ; the accessory flagellum consists 

 of a single tapering or triangular joint, shorter than the first of the principal flagellum, 

 tipped with a long seta and a shorter one. 



Lower Antennas subequal in length to the upjaer, the peduncle longer than that of the 

 upper antennas, the first joint a little expanded, the gland-cone decurrent along the side 

 of the short third joint ; the fourth joint about as long as the three preceding united, 

 subequal in length to the fourth, but broader ; the gland-cone carrying three or four setae, 

 the third, fourth, and fifth joints furnished with several groups of them ; the flagellum 

 of fifty-six joints in a large specimen, of twenty-four in a small specimen, the first joint 

 longer than any of the following. 



Upper Lip with the distal margin rounded, closely ciliated. 



Mandibles. — The cutting plate with its edge divided into seven or eight teeth, of 

 which the outermost but one is the largest ; the secondary plate on the left mandible is 

 similar to the principal, on a smaller scale ; on the right mandible it is slender, ending 

 in three or four teeth, of which one is more prominent than the others but very slender ; 

 the spine-row of nine or ten slender curved spines, showing serration on the convex 

 margin ; the molar tubercle broad and massive, the crown set with many denticles, the 



