BY C. HEDLEY. 727 



Iravadia australis, n. sp. 

 (Plate xlviii., fig. 12.) 



Shell subcylindrical, rimate, decollate; remaining whorls four 

 and a half, rapidly increasing; covered by a dense and rather 

 glossy brown epidermis. Sculpture : the last whorl is encircled by 

 eight sharp, spiral, nearly equidistant keels, about four times 

 their own width apart. On the penultimate whorl there are five 

 of such. These are perpendicularly crossed by fine raised hair 

 lines, which bead the keels and lattice the interstices. Aperture 

 white within, a little oblique, ovate, subchanelled posteriorly, 

 peristome entire, reflected, fortified without by a thick, out- 

 standing varix. Length, 5-3 mm ; breadth, 2 -25 mm. 



Hab. — Bowen, Queensland. Half a dozen examples from 

 fresh water (J. Brazier). 



Type to be preserved in the Australian Museum. 



The above is the first of the genus Iravadia* to be recorded 

 from Australia. I have not the advantage of seeing Indian 

 shells, but, according to published figures, the Australian species 

 seems to differ by more cylindrical form. 



Both Stenothyra and Iravadia may be added to the list of 

 Torresian types; in other words, are stock which Australia derived 

 from Malaysia. 



Petterdiana thaanumi, Pilsbry. 



Pilsbry, The Nautilus, xiii., Ap., 1900, p. 144. 



(Plate xlviii., fig. 11.) 



I am indebted to the author of this species for co-types obtained 

 near Cairns, Queensland. With these I have compared a series 

 from the Bellenden Ker Range in the same neighbourhood. The 

 type is 3-3 mm. in length and has four whorls; the shells from 



* Blanford, Journ. As. Soc. Bengal, Pt. ii., 1867, p. 56, PI. 2, ff. 13, 14. 

 Nearly allied if not identical seems Hydrorissoia, Bavay, Journ. de Conch, 

 xliii., 1895, p. 90. 



