Suter. — On Neiv Zealand Mollusca. 233 



Art. XIII. — Report on the Mollusca collected bij Messrs. Keith 

 Lucas and G. L. Hodghin in Six Lakes of New Zealand. 



By Henry Suter. 



[Bead before the Wellington Philosophical Society, 7th September, 1904.] 



During the year 1902 Messrs. Keith Lucas and G. L. Hodgkin, 

 of Cambridge, made a collection of the fauna of a typical series 

 of lakes in New Zealand, most of the Mollusca being obtained by 

 dredging. Before reaching New Zealand Mr. Lucas had promised 

 Mr. Charles Hedley, conchologist of the Australian Museum, 

 Sydney, to hand him over the Mollusca which would be ob- 

 tained from our lakes for study, but later on, with Mr. Hedley's 

 consent, the whole of the material was handed over to me. My 

 very best thanks are due to Messrs. Lucas and Hodgkin for 

 allowing me to study the interesting collection, and to my friend 

 Mr. Hedley for his most readily given consent. 



Mr. Lucas has published in the Geographical Journal for May 

 and June, 1904, a highly interesting and beautifully illustrated 

 report on the " Bathymetrical Survey of the Lakes of New Zea- 

 land," and Professor W. B. Benham, of Dunedin, has published* 

 the result of his study of the aquatic Oligocholia collected by 

 Messrs. Keith Lucas and Hodgkin. 



The lakes from which Mollusca were handed over to me are 

 the following : North Island — Waikare, Botoiti, Taupo, Wai- 

 karemoana ; South Island— Wakatipu, Manapouri. 



With regard to the deep-water Mollusca of our lakes nothing 

 at all was known, all the collecting hitherto done having been 

 confined to shallow water, and mostly, of course, near the shore. 

 To show how scanty our knowledge of the molluscan fauna of the 

 above-named lakes has been, it may be of interest to mention 

 that the following species have been recorded : Lake Kotoiti 

 — Sphwrium novo3-zelandio3, Desh. (as lenticula, Dk.), Potanio- 

 pyrgus badia, Gould (as fischeri, Dk.), both collected by Hoch- 

 stetter, and Melanopsis trifasciata, Gray. Lake Taupo — Diplo- 

 don menziesi, Gray (Dieffenbach), and its subsp. hochstetteri, Dk. 

 (Hochstetter). Lake Waikaremoana — Diplodon menziesi, Gray 

 (as waikarense, Colenso). Lake Wakatipu — Planorbis corinna, 

 Gray, and Isidora antipodea, Sow., both collected by Captain 

 F. W. Hutton. 



I propose to describe first, in systematical order, all the mol- 

 luscs brought together, then to give a synopsis of the molluscan 

 fauna of each lake, and finally tabulate the bathymetrical dis- 

 tribution of the species. 



* P.Z.S., 1903, vol. ii., pp. 202-232, pis. xxiv.-xxvi. 



