682 PBOCEEDINGS OF THE NATIONAL MUSEUM. 



Paranephrops setosus is nearly related to P. zealandicus, but may be 

 distiuguislied by tlie following characters: The cephalothorax is more 

 oval than in P. zealandkmSj owing to the bulging of the sides of the 

 carapace; the sides of the carapace are thickly strewn with acute, 

 forward-turned spines, which take the place of the rounded tubercles 

 in P. sealandk'us. The rostrum and antennal scale are longer, the lat- 

 eral rostral teeth longer and more spiniform; the rostrum is furuished 

 with an evident median keel, most prominent on the distal half of the 

 rostrum (in P. .::ealcmdicus there is a gastric keel, but no keel on the ros- 

 trum). These characters are manifest even in small specimens not 

 more than 65 mm. in length, although in them the carapacial spines are 

 much reduced in number — limited, indeed, to the hepatic area and the 

 parts near the cervical groove. In P. zealandicus of a similar size 

 the carapace is smooth. 



The number of s^nnes on each side of the rostrum varies between 

 three and six. In every specimen I have examined there is at least one 

 spine on the under side of the rostrum; in several individuals there 

 are two, in one individual three. 



The largest specimen before me is 145 mm. long. 



When Professor Hutton described P. setosus he was apparently 

 unacquainted with White's description of P. zealandicus,^ and his type 

 material probably included both the present species and P. zealandicus, 

 for he gives as the habitat of P. setosus "stream near Invercargill, 

 Province of Otago, and the river Avon, near Christchurch, Canter- 

 bury." The form from Invercargill is presumably (from what we know 

 of the distribution of the New Zealand crayfishes) P. zealandicus. 

 This is rendered the more certain in that Chilton- tells us that a large 

 specimen in the Otago Museum, labeled P. setosus by Professor Hutton 

 himself, has a cylindrical carapace, furnished with numerous rounded 

 tubercles — features peculiar to large specimens of P. zealandicus. 

 Button's description, however, seems to have been drawn up from the 

 Avon Eiver form, to which the name setosus may be properly restricted. 

 I have received specimens of P. setosus {seusu strictiori) from Mr. Chil- 

 ton, collected in the neighborhood of Christchurch, in the Avon and 

 Heathcote rivers, and one pair taken at Rangiora, fifteen or twenty 

 miles north of Christchurch. 



Mr. Chilton-' considers P. zealandicus and P. setosus to be one and 

 the same species. As far as can be determined from the material at 

 my disposal, the two species are i^erfectly distinct, even young, very 

 small specimens being easily distinguishable. 



List of specimens examined : 



River Avon, Christchurch, New Zealand (South Island), four males, 

 four females (Coll. Mus. Conip. Zool. and Coll. Dunediii Mus.); river 

 Heathcote, near Christchurch, New Zealand (South Island), one male, 



^ Chilton, Trans. New Zealand Inst., XXI, p. 237. 



2Ibid.,p. 248. 



3Ibid.,p.238. 



