Chilton. — 0)1 Neiv Zealand Fresh-water Crayfish. 13 



Art. V. — Note on the Fresh-ivater Crayfishes of New Zea- 

 land. 



By Charles Chilton, M.A., D Sc, M.B., CM., F.L.S., 

 Eesearch Fellow, University of Edinburgh. 



[Bead before the Philosophical Institute of Canterbury, 6th October^ 



1899.] 



Some years ago I published a paper on " The Distribution and 

 Varieties of the Fresh-water Crayfish of New Zealand."''' 

 My collection was deposited in the Dunedin Museum, and 

 shortly afterwards the whole collection, together with some 

 additional specimens afterwards collected, was, with the kind 

 consent of the late Professor T. J. Parker, forwarded to Pro- 

 fessor Walter Faxon, of Cambridge, U.S.A., for use in the 

 preparation of the second part of his " Ee vision of the Asta- 

 cidce," which was to treat of the South Hemisphere genera 

 of fresh- water ci'ayfish. Unfortunately, the material at his 

 command did not include sufidcient specimens from Australia, 

 Tasmania, and South America to enable him to complete a 

 satisf actor V revision of the ParastacincB as a whole, but such 

 results as he could obtain he has recently published iu the 

 " Proceedings of the United States National Museum,"! and in 

 this paper he deals pretty fully with the New Zealand cray- 

 fishes. As his work may not be accessible to many in New 

 Zealand, I have thought it well to give a short account of his 

 results here, especially as on one point they differ somewhat 

 from my own. 



Faxon divides the crayfishes of New Zealand into three 

 species, viz. : (1) Paranephrops planifrons, White ; (2) Parane- 

 l^hrops zealandicus, White; (3) Paranephrops setosws, Hutton. 



I had considered the last two species as merely varieties of 

 a single species, which I described in my paper under the 

 name P. nco-zelanicus, and I there mentioned most of the 

 points of difference which Faxon relies upon for the separa- 

 tion of the two species, and so long as these are recorded and 

 recognised it matters little whether we divide the specimens 

 into two species or two varieties of one species. Professor 

 Faxon has, however, had such great experience in dealing 

 with species of crayfishes that it will probably be wise to fol- 

 low him in recognising P. zealandicus and P. sctosus as sepa- 

 rate species, especially as the two names have already been 

 used. 



* Trans. N.Z. Inst., xxi., pp. 237-252, plate x. 



t Proc. U. S. National Museum, vol. xx., pp. 643-694, with plates 

 Ixii.-lxx. 



