246 Transactions. — Zoology. 



them a distinct species. With few exceptions the young shells 

 of C. novozeelandica show the characters just indicated. The 

 colour is light-grey, and the nepionic shell is distinct. The 

 dimensions of two specimens are — - Length, 3 J mm. ; height, 

 2f mm. ; diam., 1J mm. ; umbo 2 mm. from anterior end : 

 length, 2| mm. ; height, 2 mm. ; diam., 1 mm. ; umbo, 2 mm. 

 from anterior end. The mean indices are — iii. = 78; vii. = 41 ; 

 x. - 66. 



Corneocyclas hodgkini, n. sp. Fig. 9. 

 (1.) Lake Waikaremoana (Stat. 18 — Dredged in 800 ft.). — 



Two specimens. They are very small, 

 oval, much compressed, the anterior 

 side produced and attenuated ; pos- 

 terior and ventral margins regularly 

 rounded ; colour yellowish-white ; beaks 

 obtuse, unconspicuous ; nepionic shell 

 •"is-" distinct, very finely concentrically stri- 



ated, passing without change into the 

 adult valves, which are irregularly finely concentrically striate. 

 Posterior part with a ferrugineous coating. The dimensions are 

 — Length, 2| mm. ; height, 2 mm. ; diam., 1 mm. ; and the indices 

 — iii. = 72; vii. = 36: length, 2 mm.; height, If mm. ; diam., 

 | mm. ; and the indices — iii. = 87 ; vii. = 50. 



Named in honour of Mr. G. L. Hodgkin, who so ably assisted 

 Mr. Lucas in his arduous work. 

 Type in my collection. 



(2.) Lake Taupo (Stat. 10— Dredged in 280 ft. and 320 ft., 

 muddy bottom). — Six small specimens, thickly coated all over 

 with ferrugineous earth, so that the form of the shell is unrecog- 

 nisable. I succeeded in cleaning one specimen, and found it to 

 agree with the specimens just described from Lake Waikare- 

 moana. Dimensions of the cleaned specimen — Length, 3 mm. ; 

 height, 2\ mm. ; diam., 1 mm. 



Fam. HYDKOBIID^E. 



Genus Potamopyrgus, Stimpson (1865). 



Americ. Journ. Conch., vol. i., 1865, p. 53. 



Potamopyrgus corolla, Gould (1847). 



Melania corolla, Gould, Proc. Bost. Soc. Nat. Hist., vol. ii., 

 1847, p. 223. 



(1.) Lake Waikare (Stat. 19 — From reeds). — One specimen, 

 with black coating and six rounded whorls. Length, 5^ mm. ; 

 breadth, 3f mm. 



(2.) Lake Tawpo (Stat. 16 and 16f— Dredged in 280 ft. and 

 320 ft., muddy bottom). — Four specimens, all of which are 



