318 



n-half, smooth and polished, tlie anterior one angulated posteriorly, 

 the next is slightly inflated ending in a bulbiform tip. 



The posterior spire-whorls are distantly costated, the others 

 are ornamented with curved lamelliform costfe, separated by 

 little wider intervals. 



Base of body-whorl flatly-rounded, smooth, angulated at the 

 periphery ; the peripheral keel crenulated ; aperture oval, the 

 major diameter axial. 



Dimensions. — -Length, 4 ; breadth, -5. 



Locality. — Eocene ; BuUin Merri, near Camperdown (one ex.). 



The nearest ally of this new species is *S'. crehrelamellata, from 

 which it differs by its more slender shape, less crowded lamellae, 

 <ind the alDsence of spiral ornament on the base as well as on the 

 whorls ; the apex is also different, and the whorls are not so flat. 



FAMILY NATICTD.E. 



Genus Natica. 



syxopsis of species. 



Uml^ilicus with a funiculus, without posterior callosity (iI^atica, 



Shell thin, whorls slightly tabulated, funicular expansion 



thinly everted. 1. Hamiltonensis. 



Shell solid, whorls regularly convex, funicular expansion 



stout. 2. siiMXoce. 



Umbilicus more or less fllled with a funicular callosity confluent 



with tlie columella-border (Neverita). 



Umbilicus fllled with a callosity; shell hemisphaeric. 



3. gibhosa. 



Umbilicus almost concealed by posterior callosity; shell 

 oblong-oval. 4. cixumhilicata. 



Umbilicus distinctly funiculate. 



Shell narrow-oval, spire produced. 



Length more than 2 x width, an antesutural band. 



5. halteatella. 

 Length less than 2 x width, no sutural band. 



6. subvarians. 

 Shell broadly oval, spire very short ; body-whorl 



medially depressed. 7. varians. 



Shell globose-conic, whorls ventricose ; spire elevated. 



8. Wintlei. 



L^mbilicus not distinctly funiculate. 



Shell globose, spire prominent. 9. Mooraboolensis. 

 Shell hemisphivric, spire almost concealed. 



10. substolida. 



