254 Transactions. — Zoology. 



Stat. 38, but the spiral striatum is not so distinct, and the coating 

 is thicker, of a greenish hue. 



(5.) Lake Waikaremoana (Stat. 4 — Dredging in 50 ft.).- — Two 

 " dead shells," one adult with the apex broken off. They are 

 rather large, of cream colour, with four rounded but slightly 

 shouldered whorls ; distinctly spirally lirate. Columella twisted, 

 a nd aperture produced at base. Typical forms, though one 

 much larger. Shell : length, 15| mm. ; breadth, 9 mm. Aper- 

 ture : height, 10 mm. ; breadth, 5 mm. Shell : length, 10J mm. ; 

 breadth, 6 mm. Aperture : height, 7 mm. ; breadth, 3 mm. 

 Ratios : i. = 1 : 1-7; ii. = 1:2; hi. = 1 : 16. i. = 1 : 1-8; 

 ii. = 1 : 2-3; hi. = 1 : 1-5. 



(6.) Lake Waikaremoana (Stat. 5 — Dredging in 50 ft.). — Six 

 specimens, two of them quite young. The colour is light-horny, 

 some shells with a ferrugineous coating. The whorls in some are 

 rounded, in others shouldered and the keel ornamented with 

 short bristles. In young specimens the spiral striation is cmite 

 distinct. Columella twisted, and aperture produced anteriorly. 

 These again are typical forms. Dimensions of largest specimen : 

 Shell : length, 13 mm. ; breadth, 6| mm. Aperture : height, 

 8 mm. ; breadth, 4 mm. Ratios : i. = 1 : 1*9 ; ii. = 1 : 2 ; 

 iii. = 1 : 1-6. 



(7.) Lake Waikaremoana (Stat. 32 — Dredging in 10 ft. to 

 20 ft.). — Four nearly adult and four young specimens. They 

 are dirty-white, the longer examples with a light-brown coating. 

 The four whorls are convex, very little flattened below the 

 suture ; spiral striation indistinct. These shells are very nearly 

 typical. Dimensions of largest specimen : — Shell : length; 

 12 mm. ; breadth, 6| mm. Aperture : height, 8-5 mm. ; breadth, 

 4 mm. Ratios : i. = 1 : 1-8 ; ii. = 1 : 2-1 ; iii. = 1 : T4. 



Synopsis of the Molluscan Fauna of the Six Lakes. 



Lake Waikare. 



Diplodon menziesi, Gray, subsp. rugata, Hutton. 

 Corneocyclas novozeelandica, Prime. 

 Potamopyrgus corolla, Gould. 



,, ,, subsp. salleana, Fischer. 



( rundlachia lucasi, Suter. 

 Latia neritoides, Gray. 

 A in phi ] x'plea arguta, Hutton. 

 Planorbis corinna, Gray. 

 [sidora tabulata, Gould, subsp. moesta. //. Admits. 



Lake Rotoili. 



Diplodon menziesi, Gray, subsp. hochstetteri, Thinker. 

 Sphseriuni iioYa'-zi'l;iinlia\ Deshayes. 



