Cheeseman. — On the Mollusca of Auckland Isthmus, 161 



Abt. XIX. — On the Mollusca of the Vicinity of Aiickland. 



By T. F. Cheeseman, F.L.S., Curator of the Auckland 



Museum. 



[Read before the Auckland Institute, 20th Sej)tember, 1886.] 



SosiE years ago, I prepared a catalogue of the Mollusca of 

 Auckland Harbour, which was printed in vol. viii. of the 

 "Transactions of the N.Z. Institute."* Although as complete 

 as the materials at my command would permit, it contained 

 many faults, both of omission and commission. I now propose 

 to correct these mistakes : to give a complete list of the species 

 observed in the harbour, with notes on their habitats, etc, ; 

 and to add thereto a similar catalogue of the land and fresh- 

 water species inhabiting the Auckland Isthmus and its vicinity. 

 I am in hopes that the paper may be useful in two ways. 

 First, in giving to the local collector a catalogue of the species 

 which can be obtained near Auckland, together with some in- 

 formation as to where to look for them. Secondly, as a con- 

 tribution to a knowledge of the distribution within the Colony 

 of the New Zealand Mollusca, a matter which it is important 

 should be worked out, for it will give some assistance in solving 

 ma_-y questions connected with the geology and physical his- 

 tory of the country. 



For the purposes of this paper, I shall consider Auckland 

 Harbour to extend in a northerly direction as far as Lake Taka- 

 puua and Eangitoto Eeef ; and to the eastwards, to the Tamaki 

 Heads and Motutapu Island. Its western boundary would be 

 formed by a line drawn from Kauri Point to the mouth of the 

 Whau Eiver. By the term Auckland Isthmus and its vicinity, 

 I mean not only the isthmus proper, extending from the Whau 

 portage to Penrose, but also that portion of the North Shore 

 to the south of a line drawn from the head of Lucas' Creek to 

 a point on the sea-coast a little to the north of Lake Takapuna. 

 The whole district would have a greatest length of about ten 

 miles, with a greatest breadth of nine. The land area is pro- 

 bably over 60 square miles. 



In my previous paper I have given a sketch of the chief 

 physical features of the harbour, and some general remarks on 

 the local distribution of the Mollusca found therein. It would 

 be useless repeating this here ; more especially as in the ap- 

 pended catalogue I have attempted to give some information 

 as to the special localities and relative frequency of each 

 species. 



• " Trans. N.Z. Inst.," vol. viii., art. xxxvii. 

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