304 CHILTON 
This species was taken at many of the Stations, being 
extremely common at Stations 73, 74, 75. Mr. Waite informs 
me that the Crayfish was trawled in immense numbers at the 
Chatham Islands, both in Petre and Hansen Bays; the greater 
proportion were returned to the water, but eleven large sacks 
were filled and given to the Maori and Moriori inhabitants of 
the islands. It is remarkable that all the specimens taken 
proved to be males; I observed the same thing myself during a 
recent visit to Dusky Sound, in December, 1908, where many 
specimens were taken in shallow water and all proved to be 
males. On the other hand, fully half the specimens obtained in 
July and August from the shops for dissection in the Biological 
Laboratory are females. 
This species is closely allied to J. lalandii Milne-Edwards from 
the Cape of Good Hope. Parker considered J. edwardsu a 
separate species distinguished mainly by a different pattern of 
the sculpturing on the abdominal segments; at the same time 
he pointed out that the differences were shght and _ that 
specimens from other localities might necessitate the merging 
of the two forms. Ortmann subsequently combined both 
J. paulensis (Heller) from St. Paul in the Indian Ocean, and 
J. edwardsii (Hutton) with J. lalandu (M-Edw.) (see Stebbing, 
South African Crustacea, part 11., p. 38). I have not been able 
to consult Ortmann’s paper, and in the meantime leave the 
species under Hutton’s name as a matter of convenience for 
New Zealand workers. As regards questions of distribution, it is 
immaterial whether we consider it a separate species or a variety 
of J. lalandu. 
IBACUS ALTICRENATUS Spence Bate. 
Ibaccus alticrenatus Spence Bate, Chall. Rep. Macrura, xxiv., 
1888, p. 238, pl. ix., fig. 2. 
Several specimens from Stations 83 and 89, and one from the 
stomach of a Zeus at Station 30; another from Chatham Islands. 
It was also taken by the Challenger in New Zealand seas, and 
a variety has been taken off the coast of Australia. 
These specimens agree minutely with the description given 
by Spence Bate. The late Mr. F. E. Grant® described a 
variety of this species under the varietal name septemdentatus 
from specimens dredged off Port Jackson in which the distal 
margin of the antennae bore seven teeth. The number of teeth 
on this margin is however subject to variation; in one of Mr. 
Grant’s specimens there were six teeth on one side and seven on 
the other. In most of my specimens there are six teeth with a 
(3) Grant, Proc. Linn., Soc. N.S.W., 1905, p. 322, pl. xi., fig. 1. 
