Ahchey. — Fresh-water Crayfish of New Zealand . 



307 



P. setosus, for the shape of the latter is due to the narrowing of the anterior 

 part of the carapace. In fact, the measurements indicate that P. zea- 



Fig. 10. — P. zealandicus (White). Specimen from Waimate. 



landicus has a very slightly wider carapace than P. setosus. As mentioned 

 above, rounded tubercles replace the spines on the sides of the carapace 

 of P. setosus. 



The rostrum (columns 3, 4, and 5) is considerably shorter and broader 

 in P. zealandicus than in P. setosus ; there is no 

 median keel on its anterior portion, and there are 

 5 blunt tubercles on either side, and none or 1 

 on the under-surface. 



The antennal scale (columns 6 and 7 ; fig. 11) 

 also is shorter and broader in P. zealandicus than 

 in P. setosus ; the broad appearance is enhanced 

 by the fact that it tapers abruptly from half-way. 



Chelae. — The spinulation of the chelae differs 

 in certain points from that in P. setosus. On 

 the upper surface of the carpus small rounded 

 tubercles are found instead of spines ; the upper 

 surface of the propod is provided with a few 



tubercles, completely hidden by dense tufts of p IG \\ Antennal .scale of 



hair ; these tubercles are arranged irregularly P. zealandicus ; x 3. 

 posteriorly, merging to one median row an- 

 teriorly. In other respects the arrangement of the tubercles is similar 

 to that of the spines on the chelae of P. setosus (cf. fig. 9). 



Distribution op P. setosus and P. zealandicus. 



P. setosus is found only on the eastern side of the South Island, from 

 Omihi in the north to Winchester in the south. I have not obtained them 

 from among the mountains, but only from the lower parts near the coast, 

 and then not from the rapid shingle-bed rivers themselves, but from creeks 

 or pools leading into them. The results of observations by tourist parties 

 and the mountain guides, to whom application was made, as to their occur- 

 rence high above the sea-level or in the cold rapid mountain torrents are 

 entirely negative. It is to be noted that, although the Winchester speci- 



