156 GASTROCOPTA, AUSTRALIA. 



c 1 . Length 2 to 2.4 mm.; teeth rather small and 

 slender; Queensland coast. 



G. p. queenslandica, no. 95a. 

 c 2 . Length 2 mm. ; West Australian coast. 



G. mooreana, no. 96. 



a 1 . Columellar lamella horizontal in front, curving downward 

 within. 



&. Columellar lamella situated high, curving downward 

 but slightly within; shell narrow, cylindric, the 

 diam. less than half the length; 5 to 5!/3 whorls. 

 Western Australia. G. tatei, no. 100. 



& 1 . Inner end of columellar lamella rather strongly de- 

 scending; diam. about half the length; scarcely 5 

 whorls. Northern Queensland to New Guinea. 

 c. Columellar lamella of moderate size. 



G. macdonnelli, no. 99. 

 c 1 . Columellar lamella very large. 



G. m. macrodon, no. 99&. 



a 2 . Columellar lamella obliquely and steeply ascendmg in- 

 ward. 



b. Parietal lamella long and very much curved, its crest 

 flaring towards the periphery. New South Wales. 



G. hedleyi, no. 101. 



6 1 . Parietal lamella shorter, its crest not flaring out- 

 ward. 



c. Parietal lamella rather strongly curved to- 

 wards the columella within, moderately long. 

 Eastern Queensland. G. mussoni, no. 102. 



c 1 . Parietal lamella shorter and less curved. 

 Western Australia. 



d. Aperture about one-third the total length 

 of shell. 



e. No interpalatal plica. 



G. larapinta deserti, no. 103a. 

 e l . An interpalatal plica present. 



G. larapinta, no. 103. 

 d\ Aperture one-fourth the total length. 



G. wallabyensis, no. 104. 



