Suter. — On New Zealand Mollusca. 253 



length, 15 mm. ; breadth, 10 mm. Aperture : height, 10 mm. ; 

 breadth, 5*5 mm. Shell : length, 9 mm. ; breadth, 6| mm. 

 Aperture : height, 6 mm. ; breadth, 3£ mm. Katios : i. = 

 1:1-5; ii. = 1 : 1-8 ; iii. = 1 : 1-5. i. = 1:15; ii. = 1 : 1-7 ; 

 iii. = 1 : 15. 



Isidora lirata, Tenison-Woods (1879). 

 P.L.S. N.S.W., vol. iii., 1879, p. 138, pi. xiii., fig. 6. 



(1.) Lake Botoiti (Stat. 12 — From weeds in 6 ft.). — Six speci- 

 mens, one only adult. The colour is light-horny, some specimens 

 having a dark coating ; the whorls are rounded, but slightly 

 flattened below the suture, the spiral striae are present but not 

 very distinct. Aperture produced at the base, columella twisted. 

 They are slightly more ventricose than the type. Shell : length, 

 12 mm. ; breadth, 7 mm. Aperture : height, 8J mm. ; breadth, 

 4 mm. Shell : length, 10 mm. ; breadth, 6 mm. Aperture : 

 height, 7 mm. ; breadth, 3| mm. Shell : length, 8^ mm. ; breadth, 

 5^ mm. Aperture : height, 5 mm. ; breadth, 3 mm. Ratios : 

 i. = 1:1-7; ii. = 1:2-1; iii. = 1 : 1-4. i. = 1:17; ii. = 1 : 2 ; 

 iii. = 1 : 1-4. i. = 1 : 1-5 ; ii. = 1 : 1-7 ; iii. = 1 : 1-7. 



(2.) Lake Taupo (Stat. 7 — Dredged with weeds in 75 ft.). — 

 One specimen of cream colour, fragile ; four whorls, shouldered 

 down to the middle of the last whorl, carina with short bristles ; 

 shell indistinctly spirally striated ; columella twisted, aperture 

 much produced anteriorly. More ventricose than the type. 

 Shell : length, 8 mm. ; breadth, 5 mm. Aperture : height, 6 mm. ; 

 breadth, 3 mm. Ratios : i. = 1 : 16 ; ii. = 1 : 2 ; iii. = 1:1-3. 



(3.) Lake Tawpo (Stat. 38— With weeds, from 80 ft,).— 

 Many, mostly young specimens. They are of a dirty- white colour 

 with a thin whitish coating. Whorls 4, rounded, sometimes 

 flattened below the suture, beautifully regularly spirally striate. 

 Columella twisted, aperture produced anteriorly. These I con- 

 sider to be typical forms. Shell : length, 9 J mm. ; breadth, 

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

 length, 8J mm. ; breadth, 4f mm. Aperture : height, 6 mm. ; 

 breadth, ".3 mm. Shell : length, 7| mm. ; breadth, 4J mm. 

 Aperture : height, 5 mm. ; breadth, 2J mm. Ratios : i. = 

 1:1-6; ii. = 1 : 2-3 ; iii. = 1 : 1-4. i. = 1:1-8; ii. = 1:2; 

 iii. = 1 : 1-4. i. = 1 : 1-7 ; ii. = 1 : 2 ; iii. = 1 : 1-6. Fig. 16 



.. , -x ^— . ^ — ■>. shows some teeth of the 



L— -p I — Jf C—fi fan/F radula. A remarkable fea- 

 ^^ ^^^ ture are the additional den- 



c tides on the outer upper 



' '£ " side of the marginal teeth. 



(4.) Lake tawpo (Stat. 38f— With weeds, from 80 ft.).— 

 Many, mostly young shells. Very much like the specimens from 



