2 RECORDS OF THE AUSTRALIAN MUSEUM. 



very fully investigated by Nebeski,* but for this reference again 

 I am indebted to Stebbing's report. 



In addition to our present species Stebbing has described another 

 new species Ce7-apus sismithi, taken during the Challenger Expe- 

 dition at Kerguelen Island, f 



In the following detailed description of the various parts of the 

 animal I have omitted all those parts where I had nothing to add 

 to Mr. Stebbing's description. 



Head and body. — The head is produced anteriorly into a sub- 

 acute rostrum between the bases of the antennte, much in the 

 same way as is shown in Mr. Stebbing's figure of Cerajius sismithi, 

 but in none of my specimens have I noticed the rostrum to be 

 " carinate " as it is drawn and described by Mr. Stebbing in C. 

 Jlindersi. (See figures A and B.) 



The relative lengths of the various segments of the pereion of 

 the female agree well with Stebbing's description, but in the male 

 they are quite different. In this (see fig. B.) the first segment is 

 about as long as the head, the second is slightly longer, anteriorly 

 it is slightly narrower than the first segment, but about the middle 

 it suddenly widens to twice this width thus giving attachment to 

 the large and powerful second gnathopoda ; the third segment is 

 considerably shorter than the second and is also narrower anter- 

 iorly but it widens posteriorly ; the fourth is shorter again than 

 the third, as wide anteriorly, but narrowing posteriorly ; the fifth 

 segment which is so long in the female, is only a little longer than 

 the fourth and not so long as the third ; the sixth is subequal to 

 the fifth in length and breadth; the seventh is as broad but shorter. 



Upper Antennm — These agree on the whole with Stebbing's 

 description, but the first joint of the peduncle is not " much longer 

 than the second joint "; it is usually about the same length and in 

 large specimens may even be somewhat shorter. The flagellum 

 may contain as many as seven joints, usually there are more than 

 four, the number given in Stebbing's description. (See fig. a. s.) 



Lower Ante7ince. — These also differ in a few details. The fourth 

 joint is not " dilated at the base," nor " abruptly broader than the 

 preceding joint " in any of the specimens that I have examined, 

 indeed the fourth joint is usually narrowed a little at the base 

 and it articulates with only a portion of the end of the third joint 

 so that the articulation is not very strong and the fourth joint is 

 very freely movable upon the third. (See fig. a. i.) 



* " Beitriii^e zur Kentniss der Amphipoden der Adria " — Arb. Zool. 

 Inst. Wieri. Bd. III. (See Stebbing's Keport on the "Challenger" 

 Amphipoda, p. 518.) 



t Eeport on the "Challenger" Amphipoda, p. 1158, PI. cxxiv. 



