Arciiey. — Fresh-water Crayfish of New Zealand . 



303 



The following table shows the average proportions of the parts measured 

 in each of the above groups. Only those proportions which show differences 

 between the groups are given. 



Body Length 



Squame 

 Length. 



t> i t a Rostrum 

 Body Length, L h 



Rostrum 

 Length. 



Rostrum 

 Breadth. 



Rostrum 

 Spines. 



Normal group 

 Northern group . . 

 East Cook Strait group 

 West South Island group 



4-4 



1-5 



3-3 



5-5 



1 

 4-4 



B. General Description of Paranephrops setosus. (See Plate IV, 

 fig. 2, and text fig. 6; also measurements, Table 2, p. 314.) 



Paranephrops setosus is found in the rivers of Canterbury as far south 

 as "Winchester. Specimens were examined from Omihi, Rangiora, Wai- 

 makariri River. Styx River. Avon River, Heathcote River, Leeston, Peel 

 Forest, and Winchester. 



I. Carapace. 



P. setosus is distinguished by a distinctly oval carapace, narrowing 

 towards the anterior end. Specimens from Winchester and Peel Forest, 



Fig. 6. — P. setosus. Specimen from River Avon. 



however, have a less oval carapace. By comparing column 1 with column 2 

 in Table 2 it will be seen that the animals become comparativelv stouter 

 as they increase in length. 



