90 Transactions. — Zoology. 



with a needle, aud bad to leave it partly rolled up. ^ Xevertho- 

 less I succeeded in seeing some of the teeth perfectly well, 

 but I am unable to say what is their number. 



Jaw osygnath, tapering, with a narrow lamella in the 

 middle. 



Dentition : Centrid tooth quadrate, the reflesed portion 

 tricuspid, the middle cusp with its short cutting-point reach- 

 ing to the end of the base ; there are three or fom- laterals 

 exactly of the same form, and then follow some laterals with 

 the biise much broader than long and three equal cutting- 

 points. The marginals are bicuspid and acuminate. 



Mr. Harper Pease has given the name of Pitys to a group 

 of Patiilc-\^e Polynesian shells, some of which have then- 

 aperture adorned with laminge, whilst others are without. To 

 the latter ones Professor A. Mousson, in his collection, has 

 given the name of Simplicaria. Most of the conchologists 

 consider Pitys to form a group of the genus Patiila. or a genus 

 of the family of the Patuiidce. 



I think I am right in referring our sheU to Pitys. To my 

 knowledge there is no other group or genus in which it could 

 be placed at present. But the jaw and the dentition show 

 clearly that it does not belong to Patula or the Patididc?. Its 

 place is in the family of the Limacida. I never had an oppor- 

 tunity of examining the dentition of a Polynesian Pitys, and I 

 do not know whether it has ever been done or not. The ana- 

 tomical study of these moUuses would be of gi'eat interest and 

 value, and would fmTiish the necessary basis for a correct 

 classification. It is rather astonishing what a large number of 

 very different forms are now included in one group or sub- 

 genus, such as Cliaropa, Endodonta (including Pitys), and 

 many others. It is only by way of anatomical examination 

 that light can be brought into this chaos. 



It is the first time a Pitys with lamellae has been found in 

 New Zealand, and I think it to be of great value, as it gives 

 an additional proof of our former land-communication with a 

 part of Poh-nesia. 



Psyra godeti, n. sp. Plate XMI., fig. 8, a, b, 0, P. 



Shell discoidal, perforated, colour homy without any 

 markings, not shining, transparent, thin, with strong, rather 

 distant, and almost sti-aight radiate ribs, about 23 in fhe tenth 

 of an inch (9 per mm.). Spire flat. Whorls 5, slightlv 

 rounded, narrow, regularly increasing, the last not descend- 

 ing. Suture impressed. Apertiure subvertical, lunar, con- 

 siderably excavated by the penultimate whorl. Peristome 

 straight, simple, basal margin slightlv arcuated. Columellar 

 margin very short, but little reflected, slightlv thickened. 

 UmbiUcns very narrow, but open. 



