lUN lo 1892 



TUBICOLOUS AMPHIPOD — CHILTON. 



On a TUBICOLOUS AMPHIPOD from PORT JACKSON. 

 By Chas. Chilton, M.A., B.Sc. 



[With Plate I.] 



Among some Australian Crustacea sent me as exchanges by the 

 Trustees of the Australian Museum was a tube-dwelling Amphipod 

 collected in Port Jackson. There was a plentiful supply both 

 of specimens and of the tubes formed by them and after a full 

 examination and comparison of them with Mr. Stebbing's des- 

 cription and figures I have no doubt that they belong to Cerapus 

 Jiindersi, Stebbing,* a species described from a single female 

 specimen taken in Flinder's Passage during the voyage of the 

 "Challenger." Mr. Stebbing says nothing of the tube in his descrip- 

 tion, and I presume therefore, that he has not seen it. I am now 

 able to supplement his description in this respect and also to 

 describe the male of the species, and to give the points in which it 

 differs from the female, and also some interesting facts on the 

 changes in form that occur during the growth of the male. 



The genus Cerapus was originally established in 1817 by Say, 

 and the species Cerapus hihularis was afterwards fully redescribed 

 in 1880 by S. I. Smith who established for it a new sub-family 

 CerajnncB in the family Corophiidce.j He thus describes the 

 new sub-family : — 



" The single known genus differs from the Podocerince and allied 

 groups in the following characters. There are only three pairs of 

 branchial lamellfe, which are borne on the third, fourth and fifth 

 segments of the perseon, and only three pairs of ovigerous lamellae, 

 which are borne on the second, third, and fourth segments. The 

 second and third pleopods are much smaller than the first, and 

 their inner lamellfe are rudimentary or very small. The second 

 and third uropods are uniramous and nearly alike, the distal 

 extremity in each being short and terminating in a hooked joint. 



" The only known species inhabits unattached, portable tubes, 

 and, as in many allied genera, has large cement glands in the bases 

 of the first and second perjeopods." 



The above quotation has been taken from Stebbing's " Report 

 on the " Challenger " Amphipoda," as I am unable to consult 

 Professor Smith's original paper. I am therefore unable, also, to 

 compare the present species in detail with Cerapus iubularis, Say. 

 The " cement glands " in the first and second pereiopods have been 



* Report on the "Challenger " Amphipoda, p. 1163, plate cxxv. 

 t See Stebbing's Eeport of the " Challenger " Amphipoda, p. 522. 



