100 THE PROCEEDINGS OF THE LINNEAN SOCIETY 



Diam. Maj. 4^, min. 3^, alt. 2, liu. 



Hab. Palm Island, North-east Coast of Australia. 



This species varies in colour from bright chestnut to yellowish- 

 brown, and has dark irregular radiating rays. Ten specimens 

 found. 



4. — Helix (Thalassia) annulus. 



Shell minutely perforated, depressed, thin, transparent, smooth, 

 shining olivaceous or yellowish horny, spire moderately conical, 

 apex obtuse, whorls 5, slightly convex, pei'iphery I'ounded, above 

 banded with one dark-brown band running into the suture and 

 spirally to the apex ; base convex, smooth, umbilicus minute, 

 shallow, aperture nearly diagonal, lunate, peristome simple, acute, 

 margins distant, the right thin, the columellar margin whitish, 

 thickened, slightly reflected. 



Diam. Maj. 6^, min. 5J, alt. 3, lin. 



Hab. Banks of Katow River, New Guinea. 



This thin transparent species . was found at the village of 

 Marrahata, mouth of Katow River, near the seashore, in moist 

 places under cocoanut trees, living in clusters inside of old cocoa 

 husks. Three dead and one living specimen were found at Dunge- 

 ness Island, Torres' Straits, about 40 miles south from Katow. 

 They may have been carried on drift timber and palm roots which 

 are to be seen floating in the Straits after the North-west 

 Monsoons. 



5. — Helix (Thalassia) Sappho. 



Shell perforated, orbicularly depressed, thin, sub-pellucid, nearly 

 smooth, glossy, horny, whorls 44, slightly convex, the last large 

 and rounded at the periphery, suture flattened, spire obtuse, base 

 convex, having strise running into the umbilicus, aperture diagonal, 

 ovately lunate, peristome thin, margins distant, the upper and 

 outer very thin, columellar margin thickened into a white callus, 

 grooved in the middle, reflected partly over the umbilicus like a 

 spout. 



Diam. Maj. 3£, min. 2f, alt. 1| lin. 



Hab. Yule Island, New Guinea. 



