Phreatogammarus propinquus, Chilton.

Phreatogammarus propinquus, Chilton in Ann. Nat. Hist., ser. 7, vol. xix, pp. 388–90, pl. xi (1907).

This species was described in 1907 from a single imperfect specimen collected by Mr. Crosby Smith in a small pool near the top of Mount Anglem, in Stewart Island, at a height of about 2,800 ft. above sea-level. In February, 1908, I obtained a few specimens from a small stream at Rona Bay, in Wellington Harbour. The place at which they were obtained is only a short distance above high-water mark, but the water was quite fresh, and the species was found in association with Parorchestia tenuis (Dana) and other fresh-water animals. I also have had for many years a mounted specimen sent me from Greymouth by Mr. R. Helms, which I had not previously been able to recognise with certainty, but which I can now tell from comparison with Rona Bay specimens is undoubtedly a female specimen of this species.

The species is of special interest owing to its relationship to the subterranean species Phreatogammarus fragilis (Chilton) from the underground waters of the Canterbury Plains. In describing P. propinquus I pointed out that the generic characters given by Mr. Stebbing required slight modification in order to admit the species. In the specimen then described it was impossible to say whether eyes were present or not, owing to its imperfect condition; in the Rona Bay and Greymouth specimens, however, the eyes are present and well marked, so that the character “without eyes” included in Mr. Stebbing's generic diagnosis will also have to be struck out, and the genus Phreatogammarus is thus shown to be still nearer to Gammarus.

The Rona Bay specimens appear to be closely similar to the Mount Anglem specimens originally described, except as regards the 2nd gnathopods. In a female specimen, bearing eggs, from Rona Bay, the 2nd gnathopod is somewhat more similar in general appearance to the 1st, having the carpus moderately long (about two-thirds as long as the propod) and subtriangular in shape. The posterior margin of the carpus bears 3 or 4 short transverse rows of long setae, and there are 2 tufts of setae on the anterior margin, one tuft being at the distal end of the joint; and there is a row of about 7 or 8 setae on the side of the carpus along its distal border. The propod is suboblong in shape; its anterior margin bears 5 short transverse rows of long setae, the last one, at the joint of the finger, being the longest, and containing the most setae; the palm is slightly oblique, and is bordered by a double row of stout setae, which diminish in size towards the base of the finger, those at the place where the point of the finger impinges being the largest, and fairly well defining the palm; the posterior border bears a number of long setae, and other tufts of setae are situated on the sides of the joint, some of the longest being arranged close to and parallel to the palm; the finger has the inner margin minutely serrate, the serrations being closely approximated. The whole gnathopod is somewhat larger than the 1st gnathopod, in which the carpus is considerably longer, being longer than the propod, and bears a more well-marked row of setae along its distal border; the propod is somewhat narrow at the base, and has the palm more transverse, but in other