3. Paranephrops setosus, Hutton.

Paranephrops setosus, Hutton, Ann. Mag. Nat. Hist., 4th ser xii., p. 402 (1873); Chilton, Trans. N.Z. Inst., xv., p. 150, pls. xix-xxi. (1882). Paranephrops neo-zelanicus, Chilton (in part), Trans. N.Z. Inst., xxi., pp. 246, 249, pl. x., figs, 1a, 2a. (1888). Paranephrops setosus, Faxon, Proc. United States Nat. Mus., xx., p. 681 (1898).

Faxon regards this species as distinguished from P. zealandicus by the following characters: “The cephalothorax is more oval than in P. zealandicus, 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. zealandicus. The rostrum and antennal scale are longer, the lateral rostral teeth longer and more spiniform; the rostrum is furnished with an evident median keel, most prominent on the distal half of the rostrum (in P. zealandicus there is a gastric keel, but no keel on the rostrum).”

The species as thus restricted has been recorded only from the Avon and Heathcote, at Christchurch, and from streams at Rangiora. The largest specimen examined was 145 mm. in length.