256 Transactions.—Z oology. 
Length of largest specimen +56 inch. 
Hab. Lyttelton Harbour; Worser Bay, Wellington (T. W. Kirk); 
Port Jackson (W. A, Haswell). 
The differences between this species and Podocerus cylindricus, Say, have 
already been mentioned in the general comparison of specimens from the 
different localities ; but for the sake of greater clearness 1 will recapitulate 
them. 
Flagellum of lower antenna is as long, or very nearly as long, as the last 
joint of peduncle, the stout spines found on the end of it are not de- 
veloped into hooks. The inner margin of dactylos of first gnathopod is only 
roughened in the female, and in the male the serrations, though sometimes 
as great as in P. cylindricus, vary. The second gnathopod is larger than in 
P. cylindricus, and is much larger in the male than in the female. In P. 
cylindricus the female differs from the male only in “ the slightly smaller 
size of the propodos of second pair gnathopoda;” the second gnathopod of 
female also differs considerably in shape from that of the male. There is a 
blunt tooth at the distal end of the concave margin of propodos (of male) ; 
not found in P. cylindricus. The concave margin of the dactylos is smooth | 
in the male, in female roughened on proximal part only. 
These differences, though somewhat numerous, are none of them of very 
great importance; and, if P. cylindricus varies as much as P. longimanus, I 
dare say it would be difficult to find constant differences of any importance 
between the two species. In considering the question it must be remembered 
that there are other similar cases: Paranthura costana, Philowgria rosea, 
Lysianassa magellanica, Pinnotheres. pisum, etc.: this, however, is not the 
place to discuss the general question of the occurrence of the same species 
in both the northern and the southern seas. 
Nore.—-My reasons for considering the two animals described above as 
male and female of the same species are these :—(1) They resemble one 
another so closely in everything but the gnathopoda that they must be 
considered as belonging to the same species; (2) the form with the small 
gnathopoda is certainly a female, for I havé frequently seen specimens 
carrying eggs ; (3) the form with the large gnathopoda I have never seen 
bearing eggs. 
The large gnathopoda of the male are only possessed by fully-grown 
specimens. In very young animals they are more like those of the female, 
having the palm extending only about half way along the inferior edge of 
the propodos and defined by two or three stout sete. In slightly older 
specimens the palm is longer, until it extends along the whole length of the 
margin of the propodos, and finally the sete are cast off and the gnathopod 
assumes the form already described. 
