300 C. T. Trechmann — Cretaceous Mollusca 



and is rather depressed. The body-whorl is large and globose and 

 increases rapidly in size. The surface is rather eroded and bears 

 closely spaced rather foliaceous growth-lines. The suture is some- 

 what deep and the whorls are not flattened below it, and there are no 

 parallel strice on the basal part of the body-whorl. It measures 

 16 mm. high and resembles a specimen figured by Jack & Etheridge, 

 pi. xxxi, fig. 2. Another specimen (Fig. 9) differs in having 

 a more elevated spire, the suture is not insunken and the whorls are 

 flattened just below it, and the body-whorl is relatively smaller and 

 less swollen. About six fine rounded concentric ridges occupy the 

 base of the body-whorl near the umbilicus, and the growth-lines are 

 much less strongly marked than in the first variety. It is smaller 

 in size and resembles the specimen figured by Jack & Etheridge,pl.xxxi, 

 fig. 3. Another smaller specimen (Fig. 10, x 1% iiat. size) resembles 

 the last, but the concentric ridges occupy the whole of the body-whorl.. 



This shell agrees in everyway with the Australian form, and is the 

 only Australian Cretaceous fossil I found in the New Zealand rocks. 

 Mr. E. JJ. Newton has recently discussed the generic affinities of this 

 shell in a paper quoted above dealing with the fossils of the opal 

 deposits of the interior of New South Wales. 



It occurs in the Rolling Downs Formation of the Lower Cretaceous, 

 and also in the Desert Sandstone, Upper Cretaceous, in Australia. 

 I have a specimen from the opal deposits of Whitecliffs, New 

 South Wales. 



Locality. — Selwyn Rapids, where it is not scarce. I did not find it 

 in any other locality, and this is the first record of the occurrence of 

 this typically Australian form in New Zealand and forms the sole 

 connecting link among my specimens with the Australian Cretaceous. 



Neritopsis (?) Speighti, sp. nov. (PI. XIX, Figs. 12-15. l ) 



The shell consists of four or five whorls, and in young specimens 

 is thin and oval in shape. In the adult state it is more rounded 

 owing to flattening of the spire and rapid enlargement of the body- 

 whorl. The spire in immature specimens is pointed and rather 

 elevated, but in the adult specimen it is flattened through erosion or 

 Avear. In the largest example there is a faint umbilicus, the peristome 

 is entire, and the inner lip is somewhat detached from the body- whorl. 

 The lip is thickened for some distance back from the margin, but 

 ends in a sharp rim. The body-whorl is decorated witli about 

 fifteen raised concentric parallel rounded ridges, alternating with 

 furrows of about the same width and depth. On the earlier whorls 

 the furrows are less strongly marked. The growth-lines are rather 

 faint, but are interrupted here and there on the body-whorl by 

 a strong furrow. 



In the absence of knowledge of the operculum or of the animal it 

 is impossible to fix with certainty the genus of this shell, as many 

 genera quite unallied to one another develop parallel concentric 

 furrows, such as Cinulia, Dolium, Pyrula, Fossarus, and many others. 



The moderate thickness of the shell and increasing thickness of 

 the adult lip and sharpness of the aperture point to Neritopsis 



1 Fig. 15 is x 2 nat. size. 



