Marwicx.—Naticidae and Naricidae of New Zealand. 545 
The Tertiary and Recent Naticidae and Naricidae of New Zealand. 
By J. Marwick, M.A., D.Sc. 
[Read, by permission of the Director of the N.Z. Geological Survey, before the Wellington 
Philosophical Booka. 10th October, 1923 ; eal by Editor, 22nd December, 1923 ; 
published separately, 28th August, 1924.] 
Plates 55-60. 
I. Family NATICIDAE. 
A SATISFACTORY classification of the Naticidae is, for the following reasons, 
difficult to carry out: (1) The importance that has been attributed 
by most authors to the calcareous or horny nature of the operculum ; 
(2) the use of the funicle in classification ; (3) the eie of sculpture ; 
(4) the great variability in shape within many of the speci 
1. Cossmann (1919, p. 385) criticizes the system of кыне division 
according to the nature of the operculum, and cites Natica dillwynni Payr. 
as the possessor of an operculum partly horny and partly calcareous. 
2. The umbilical funicle is by no means a constant, and when coalescent 
with the parietal callus loses its individuality. In some cases—e.g., N. maoria 
—it becomes quite obsolete 
3. The only sculpture is of simple spiral grooves and cords. On Sinum 
and its allies this is well developed, but is of a very uniform nature through- 
out. In the other Vie weak spirals are often present, particularly in some 
of E m Uber spp., but here they do not have even specific significance. 
Dall (1892, p. 362) says, * The males, as usual, are apt to be smaller, 
ai “not having to carry the enormous egg-sac of the females, have the 
‘shoulder ’ of the shell, or that part of the whorl just in front of the suture, 
less inflated, giving the whole shell a more evenly conical and less scalar 
spire. ese differences are more ma in the group having a corneous 
operculum, but are perceptible in the others, expecially those with an elevated 
spire. Apart from sexual differences, th ce ariability about the 
and two new subgenera. is proposed for some of the shells 
classed under — ee by Suter and under Lunatia by 
Hutton; Globisinum he globose shells with spiral sculpture classed 
sometimes as Sinum ud sometimes as Ampullina; Magnatica and 
Carinacca for Naticoid groups, the latter of which was placed under Lunatia 
by Hutton and Ampullina by Suter, the former under Polinices by Suter. 
The table of generic and subgeneric ranges reveals no important additions 
to the New Zealand fauna since Bortonian times. (The one рсе 
unaticina cincta, as state sem below, is based on a single specim 
doubtful authenticity.) At first sight this might seem to point в ап 
isolation of the area during that time, preventing the arrival of new 
forms. Judging from our limited knowle edge, — the generic con- 
stitution of neighbouring areas does not seem to have been very different 
ur own. Thus new arrivals might not be notice 
18— Trans. 
