REPORT ON THE AMPHIPODA. 919 



which have long setas. spiniform and plumose like those at the apices of the peduncular 

 joints; the one-jointed accessory flagellum as long, or nearly so, as the first of the 

 principal, tipped with a long plumose seta and a shorter one. In those specimens of 

 Atyloides australis which are comparable in size with the specimen here described, the 

 proportions of the joints of the peduncle differ, and the present specimen has more 

 groups of setae than larger specimens of the allied species. 



Lower Antenna} with the fourth joint shorter than the fifth ; the flagellum of eighteen 

 joints, the first longer than any of the others, showing within the markings of the new 

 joints preparing for the next exuviation, an appearance not unusual, and observed also 

 in specimens of the allied species. 



Upper Lip. — The distal part shallower and more broadly rounded than in Atyloides 

 australis. 



Mandibles. — On the cutting plate of the left mandible there are two denticles out- 

 side the most prominent tooth, while Atyloides australis has apparently only one in that 

 position. 



First Maxillae. — There are six plumose seta? on the oblique distal margin of the inner 

 plate, the apical the largest, and eleven spines on the distal margin of the outer plate, 

 similar in structure to those of the kindred species. 



Maxillipeds. — On the outer plates there are five spine-teeth on the distal part of the 

 inner margin, not set so closely together as the more numerous teeth in the other species ; 

 the finger is rather longer in proportion to the third joint, and has a long cilium on the 

 back, set further back from the base of the nail than in Atyloides australis. 



First Gnathopods. — Side-plates somewhat squared below ; on the inner surface of the 

 hand there are six small groups of spines in line, beginning near the base, the sixth being 

 on the front margin not far from the apex ; in the large specimens of Atyloides australis 

 there are five groups rather differently arranged, and in the small specimens four groups ; 

 the palm in the present species is more oblique, the finger reaching just beyond it as in 

 the adult male of the other species. 



Second Gnathopods.— These, like the first gnathopods, have few setules on the front 

 margin of the first joint instead of many as in Atyloides australis, and the palm more 

 oblique and more groups of spines on the inner surface of the hand than in that 

 species. 



Perteopods all broken below the third joint, the remaining portions not showing any 

 characteristic difference from those of Atyloides australis. 



Pleopods. — Cleft spines two or three, joints of the rami ten or eleven. 



TJropods similar to those of Atyloides australis, except that the rami of the second 

 pair appeared to be subequal, the outer rather the longer ; but as the tips were damaged, 

 this is a little doubtful, the fewness of the spines on peduncles and rami of all the pairs 

 might be due to the smallness of the specimen. 



