480 Transactions. 
New Zealand Tertiary Rissoids. 
By H. J. Fintay, M.Sc., Edmond Fellow of Otago University. 
[Read ee the Otago 1 nstitute, 12th December, 1922 ; received by Editor, 31st December, 
1923 ; issued separately, 30th July, 1924.) 
Rissorps are not usually plentiful as fossils in New Zealand. In the latest 
list id our peel fn sese (Suter, 1918) nine douce of Rissoa 2 
Castlecliff, one from Awamoa (Miocene), and the remaining three were 
discovered fossil subsequent to their ees dn as 07 D sinon The AUN | 
only addition made to this number is oina (?) 
obliquecostata М. & M., described by Marshall ud авс T9900] from 
ampden. 
Although these small shells are termed Rissoids, TM (1915) has shown 
that the type name, Rissoa, should not be applied to any Neozelanic shells, 
and has provided a series of generic names to cover austral forms. 
scheme marks à decided advance in their treatment, and by it New Zealand 
Recent Нива can be reduced to some semblance of order. Strong 
сома to define a new genus—e.g., [Ex ies proposing it for shells 
grouped around Rissoa cheilostoma "Ten.-Woods," but this is extremely 
unsatisfactory for workers who have not access to large suites of actual 
specimens, and have to rely mostly on literature. To ensure immediate 
pc and керне of new genera a résumé of diagnostic characters 
rative. From Iredale’s treatment of the Rissoids it was almost 
ааыа that when his names did come into use some of them should be 
misapplied, and this has already occurred. The genus Estea, in particular, 
seems to have given trouble—the writer has seen one of the foal lirate 
species determined as a Subonoba; and, further, Marshall and urdoch 
(19208) have listed Rissoa semisculcata Hutt. as a Lironoba, to which genus 
it bears little resemblance. As far as the writer can see, the following 
diagnostic notes (compiled after ^ of New Zealand Recent and fossil 
species) represent Iredale’s ideas fairly correctly; he would, however, 
have saved Neozelanic workers much trouble had he given a similar table 
when his genera were proposed. 
