240 Transactions. — Zoology. 



instance, those from Nelson) are very spiny, while many of P. 

 neo-zelanicus have the carapace almost smooth. In P. j^lani- 

 frons, again, the infero-posterior corner of the pleura of the 

 abdominal segments is usually distinctly angular, while it is 

 more or less rounded in P. nco-zelanic^is ; but this character, 

 again, varies considerably in both species. The character that 

 I have found most useful in distinguishing the two species is 

 in the form, &c., of the gi-eat claws. In P. jilanifrons these are 

 long, and have the basal portion of the propodos (without the 

 fixed finger, that is) usually fully twice as long as the carpus, 

 and generally more than twice as long as broad ; and, though it 

 sometimes bears a few scattered hairs, these are never abun- 

 dant and are not' arranged in tufts. In P. neo-zclanicns the 

 propodos is usually somewhat compressed, it is generally less 

 than twice as long as the carpus, and not more than twice as 

 long as broad, and it is always abundantly covered with hairs 

 arranged in tufts. The relative sizes of the different joints 

 vary to a considerable extent ; but I have found the abundant 

 hairs in all my specimens of P. neo-zelanicus, and this 

 forms the only character that I have been able to rely 

 upon in all cases to distinguish this species from P. j^lani- 

 frons. 



It has generally been stated hitherto that P. i^lf^f^iffons 

 is confined to the North Island and is not found in the South, 

 but is represented there by P. neo-zelanicus. In August, 1883, 

 however, I received from the late Mr. J. C. Gully two very 

 fine specimens of P. 2^lo.nifrons from a stream — the Maitai — at 

 Nelson. It would hence appear that Cook Strait has not 

 proved so great, or, rather, so old a barrier to these crayfish as 

 the mountains in Nelson forming the northern continuation of 

 the Southern x\lps. As this point seemed to be of some im- 

 portance in connection with the geographical distribution of 

 the fauna of New Zealand, and as I was ignorant of the con- 

 figuration of that part of the South Island, I applied to Pro- 

 fessor Hutton for information. With his characteristic kind- 

 ness and promptness he at once told me that there was no 

 great division (by mountains, that is) between Nelson and 

 Greymouth, but that the first great division would be along the 

 Kaikoura Mountains and across westerly to Mount Franklin, 

 and then down the Spencer Mountains and the Southern Alps ; 

 though the part between the Kaikoura Mountains and Mount 

 Franklin is much broken by rivers, some running north and 

 some south. He also told me that several North Island 

 plants extend to Nelson and down the west coast to Westport 

 and Greymouth. Another fact pointing in the same direction 

 is found in the distribution of Armadillo speciosus, a terres- 

 trial isopod. This is known from the North Island (Bay of 

 Islands, Dana, and Wellington, Hutton), and I have specimens 



