203 



2. Inner lip tuberculate or tooth-ridged, not dentate-sulcate 

 (also C. sphcerodoma, pars), or edentulous. 

 Anterior canal much produced, depressed. 



Shell pyriform ; aperture almost edentulous. 



19. C . platyrhyncha 

 Anterior canal short. 



Shell broadly oval, with a low convex back ; anterior 

 canal straight ; both lips dentate throughout. 



20. C. amygdaUna. 

 Shell oval, very large, back very gibbous, anterior canal 



upturned ; aperture almost edentulous. 



21. C. gig as. 

 Shell spheroidal, very large. 22. C. dorsata. 



III. Base flat, dilated into a horizontal circular disk. 



Shell oval, very gibbous. 23. C. gastroylax- 



EXCLUDED SPECIES. 



C. oviformis, Sow., is attributed to Tenison- Woods as author^ 

 and to South Australia for habitat, by Johnston in Geol. Tas- 

 mania, 1888; but Tenison-Woods refers (Geo. Obs. in S. Aust., 

 p. 83, 1862) to this species as a London Clay fossil, and not as 

 occurring in South Australia. 



1. Cyppaea parallela, spec. nov. 



Shell cylindrical, twice as long as wide; the spire exsert, around 

 which the body-whorl is flatly rounded ; the longitudinal curva- 

 ture of the back is interrupted at intervals, which gives rise to the 

 appearance of spiral threads, usually conspicuous towards the two 

 ends, but is sometimes obsolete. 



The aperture is shortly produced into a bluntly-pointed canal 

 at the ends, narrowed at the front. The outer lip is margined at 

 the two extremities, leaving a median unmargined portion of 

 variable length ; the teeth are small and numerous (about thirty). 

 The inner lip is thickened, and slightly projecting posteriorly ; 

 there are about twenty teeth in its whole length ; the columella 

 projects internally towards the front as a broad, concave, ridged 

 plate. 



Dimensions. — Length, 18 ; width, 9 ; height, 8. 



Locality. — Eocene; Muddy Creek. 



This species resembles dwarfed examples of C. Isabella, Linn.^ 

 of the Indo-Australian region, but has an exsert spire, and is- 

 slightly more narrowed at the front. 



2. Cyppsea sealena, spec. nov. 

 Shell oval-oblong, somewhat gibbous, highest near the middle, 

 with a steep slope anteriorly and rather abruptly narrowed at 



