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



whicli Boeck constitutes the subfamily Gammarinse, and there perhaps it ought to stand. 

 It is excluded from the CEdiceridse by the large size of the upper antennae and the small 

 size of the fifth peraeopods, as well as by having an accessory flagellum, though a small 

 one, on the upper antennae. In the species here assigned to the genus the fifth 

 perseopods are undetermined, being imperfect in our single specimen, the upper antennae 

 have an appendage which can only very doubtfully be regarded as an accessory flagellum, 

 and the third joint of the mandibular palp is longer than the second, instead of shorter 

 as in Heller's species. In placing the Challenger species next to CEdiceroides ornata, I 

 was influenced by the similarity in the maudibles, maxillipeds, ghathopods, and telson, 

 as well as in the palp of the first maxillae, though, it must be allowed, the outer plates 

 of those organs differ in the number of apical spines. On the other hand, the general 

 structure of the body and the character of the peraeopods, so far as observed, bring 

 AmathiUopsis anstralis near to the genus Einmeria, but the maxillipeds are an obstacle 

 to including it in the family Epimeridae. Owing to the imperfect condition of the fifth 

 peraeopods in the specimen, the generic position of our species is itself a little uncertain, 

 so that a more accurate determination of its family must await more favourable circum- 

 stances. 



AmathiUopsis australis, Stebbing (PI. LXV.). 



1883. AmatJiillojysis australis, Stebbing, Ann. and Mag. Nat. Hist., ser. 5, vol. xi. p. 205. 



Eostrum small, with the apex a little depressed, not projecting as far as the lateral 

 processes of the head ; these are narrow, apically almost pointed, grooved on the outer 

 surface ; the lower margin of the head carinate ; a longitudinal groove sweeps round from 

 that of the lateral process almost to the hind margin, another groove descending from 

 it transversely to a little angled point in the lower margin. A carina traverses the centre 

 of the back, leaving the rostrum smooth, and likewise a small piece at the base of each 

 segment ; along the head and first four segments of the peraeon it is a mere raised line, 

 though raised sufficiently to show a little undulation on a lateral view ; on the three 

 following segments of the peraeon and the first three of the pleon it is prolonged into 

 acute processes, successively larger, and each overlapping the next following segment, 

 that on the third segment of the pleon having its lower edge, not as in the other cases 

 continuous with the hinder margin of the segment, but originating a little in advance of 

 it ; on the fourth segment the carina is indicated beyond the dorsal depression, but does 

 not reach the end of the segment, it traverses the fifth, and is just indicated at the end of 

 the sixth segment. All the peraeon -segments have on each side a dimple or oblique 

 groove, and on the first three pleon-segments rather higher up there is an arched groove not 

 dimpled, these three segments have the hinder borders sinuous, and at the postero-lateral 

 angle the first rather tends to form a tooth than actually develops one ; in the second 



