TUBICOLOUS AMPHIPOD — CHILTON. 
1 
On a TUBICOLOUS AMPHIPOD from POUT 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 
flindersi , 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 tubularis was afterwards fully redescribed 
in 1880 by S. I. Smith who established for it a new sub-family 
Gerapince in the family Corophiidce. f 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 lamellae, 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 lamellae 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 perseopods.” 
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 tubularis , Say. 
The “ cement glands ” in the first and second pereiopods have been 
# Report on the “ Challenger ” Amphipoda, p. 1163, plate cxxv. 
f See Stebbing’s Report of the “ Challenger Amphipoda, p. 522. 
A 
