Cumron.—On Astacus fluviatilis and Paranephrops setosus. 151 
I have seen P. setosus only. P. planifrons is a perfectly distinct species, 
and is found abundantly in many places in the North Island of New Zea- 
land. P. setosus is not known to occur in the North Island, but it is widely 
distributed in the South Island, being found in the River Avon, Christ- 
church, from which the specimens for this paper were obtained, and also in 
the rivers near Invereargill, at the south of the island. Thus P. planifrons 
appears to be confined to the North Island, and to be represented in the 
South Island by P. setosus. 
P. zealandicus was described as belonging to New Zealand by White in 
1847,* but it does not appear to have been since recognized. Professor 
Hutton, who at the time when he described P. setosus in 1873+ had no 
opportunity of consulting White's description, tells me that he thinks it 
very probable that P. zealandicus is nothing more than a young specimen of 
P.setosus. From the comparison of the two descriptions in Miers' Cata- 
logue, and from the figure in the Zoology of the Voyage of the Erebus 
and Terror, this appears very likely to be the case, and it also agrees well 
with the small size of P. zealandicus (8 inches) as compared with that of 
P. setosus (52 inches). 
With regard to P. zealandicus, Mr. Miers says :} ‘‘ This species is cer- 
tainly distinct from P. setosus, Hutton. In P. zealandicus, of which the 
type specimens are in the British Museum Collections, the hands are 
clothed externally with tufts of hair arranged in longitudinal series, and 
are armed with spines only upon the superior margins, and the sides of the 
carapace are smooth. In P. setosus there are spines arranged seriately 
upon the external surface as well as the upper margin of the hand, and the 
branchial and hepatic regions of the carapace are armed with numerous 
inequal conical spines.” The first point will certainly not serve to distin- 
guish the two species, for there are tufts of hair on the hand of P. setosus, 
there having been a slight mistake in Professor Hutton’s description (see 
below). With regard to the other points they are certainly subject to some 
variation in P. setosus, and it is quite possible that the spines on the hands 
and on the sides of the carapace may be developed only in the older speci- 
mens, but I have not been able to examine a sufficiently large number of 
specimens to give a decisive answer on this point. However, there are 
certainly only the two species, P. planifrons and P. setosus, known to New 
Zealand collectors, and this leads one to think either that P. zealandicus is 
not a distinct species or that the locality given is wrong, and that it belongs 
to Fiji, where a species of Paranephrops is found.§ 
* Proc. Zool. Soc , p. 123. 
1 Ann. & Mag. Nat. Hist., ser. 4, xii., p. 402. 
+ Ann. & Mag. Nat. Hist., ser. 4, vol. xviii., 1876, p. 412. 
$ Huxley, “ The Crayfish,” p. 306. 
