REPORT ON THE AMPHIPODA. 1073 



" As to other points almost as in the genus Microdeutopus." 



In describing the subfamily Microdeutopinae, Boeck says that the third joint of 

 the elongate mandibular palp is apically obtuse, rounded ; that the first maxilla? have 

 the inner plate small, and the second maxillae the plates very broad, that the maxillipeds 

 have the outer plates armed with teeth, and the last joint of the palp apically armed 

 with two strong curved spines ; that the flagellum of the lower antennas is not very 

 long, that the uropods are biramous and the telson thick. In the definition of 

 Microdeutopus, Costa, he says (see p. 1082) that the upper antennas have the third joint 

 of the peduncle short, and that the third uropods have rami of almost equal length. Mr. 

 Chilton is of opinion that Microdeutopus ought to become a synonym of Aora, the 

 females being practically undistinguishable. M. Chevreux, on the other hand, hopes 

 to be able to publish characters by which the very simdar females of Aora, Micro- 

 deutopus, and Stimpsonia may be discriminated. 



Aora kergueleni, n. sp. (PL CIX. figs. A. $, D. % ). 



Rostrum minute, lateral lobes of the head broadly convex, little prominent, lower angles 

 of the head acute ; postero-lateral angles of the first three pleon-segments rounded. 



Eyes small, tending to oval, situated on, but by no means filling, the lateral lobes 

 of the head. 



Upper Antennse. — First joint long and thick. The other joints missing in the speci- 

 men figured, but in a second specimen resembling those of Aora trichobostrychus, the 

 flagellum with thirty-three joints. 



Lower Antennse. — The first two joints short, the gland-cone decurrent; the third 

 joint longer than the preceding two united, with some small stout spines at the apex ; 

 these three joints united not as long as the first of the upper antennas. The other joints 

 missing in the specimen figured ; in another specimen the fourth and fifth joints were 

 equal in length ; the flagellum of eleven joints, was scarcely so long as the fifth joint of 

 the peduncle. 



Upper Lip. — The distal margin describes a broad curve, much projecting at the 

 central part, the middle of which is smooth, except that straight spine-like cilia project a 

 little from the inner surface, while a brush of cilia is directed towards it from the margin 

 on either side. 



Mandibles. — The cutting edge has six teeth ; the secondary plate of the left 

 mandible probably has five ; that of the right mandible, fig. m. A., is very narrow, 

 showing only two distinct teeth, but it probably has two or three denticles as well; 

 the spine-row consists of four broad overlapping spines, the oblique distal margin of 

 which is cut into denticles ; the spines are followed by two or three plumose setae ; 

 the molar tubercle is prominent, the crown surrounded with long teeth, and its 



(ZOOL. CHALL. EXP. — PAET LXVII. 1887.) XxX 135 



