250 



ANATOMICAL NOTES ON THE HELICID/E ; 



The specimen (immature) which furnished these details wag 

 collected by Mr. Wild at Upper Nerang Creek. 



Helix delta, Ptr. — Jaw low, arcuate ; ends rounded, recurved ; 

 with a blunt mcd ; an inferior projection, crossed by numerous fine 

 folds. The rachidian tootli of the odontophore has its base of 

 attachment rather longer than wide, posterior lateral angles nearly 

 square ; anterior margin broadly reflected bearing a central slender 

 median cusp projecting beyond the posterior margin, and two 

 accessory cusps not reaching the centre of the basal plate. The 

 transverse rows of laterals are very slightly curved. The first dozen 

 laterals are with difficulty distinguished from the rachMian by the 

 slightly inclined median cusp and rounde I anterior basal margin. 

 Beyond them the distal accessory cusp diminishes, and the proximal 

 increases, until it equals in size the original median. The extreme 

 marginals offer an irregularly serrated edge. 



The specimen examined was collected by Mr. Wild at Little 

 Nerang Creek. 



Bulimus mastei.ii, Cox. — .Jaw high, arched, ends acuminately 

 rounded, centre plain, each side crossed by seven oblique folds 



Racliid an tooth with base expanded posteriorly, broadly 

 reflected, tapering to a single rounded cusp whose apex djes not 

 attain the posterior margin. The first six laterals possess a large 

 lanceolate cusp and a small distal accessary cusp. The extreme 

 marginals are forty five ranks distant from the rachidian and are 

 irregularly dentate. 



Helix iwrinjlata, Pir. — Jaw low, slightly arched, boomerang 

 shaped, tapering to the rounded ends, central moiety crossed by 

 eight stout ribs as wide as their interstices, which denticulate the 

 convex but not the concave margin, ends smooth. 



Rachidian tooth with the base of attachment longer than broad, 

 posteriorly slightly expanded, reflection tapering to a single blunt 

 cusp whose apex attains four-fifths of the length of the base : lateral 

 teeth about fifteen, much the same size, with a single large ovate 



