158 AMASTRA, OAHU. 



described by Swainson. Subsequent to these pioneer collec- 

 tions the work was taken up by Neweomb, Frick (whose shells 

 were described by Pfeiffer), Gulick, and after the lapse of 

 many years by Baldwin, bringing us to the workers of to-day, 

 who have begun a new period of 'active investigation of this 

 wonderful fauna. 



Key to O'ahuan Amastrce. 



a. Shell umbilicate ; embryonic whorls smooth. 



Cydamastra, p. 158. 



a 1 . Shell imperf orate or narrowly rimate. 

 b. Sinistral. 



c. Ovate-conic, rather stout. A. thaanumi, no. 22. 

 c 1 . Oblong- turreted, slender. A. elongata, no. 54. 

 6 1 . Dextral. 



c. Shell turreted or pyramidal, often banded. 



Paramastra, p. 208. 

 c 1 . Shell ovate, oblong or globose-conic. 



d. Curve below the columellar lamella well 



rounded. Amastrella, p. 191. 



d 1 . Curve below lamella narrow, spout-like. 



Metamastra. 

 e. Stout, often variegated, variegata 



group, p. 163. 



e 1 . Slender, spire concavely conic, cor- 

 nea group, p. 187. 



The following Amastrse are enumerated without descrip- 

 tions in Baldwin, Catalogue Land and Fresh-Water Shells of 

 the Hawaiian Islands, 1893. 



Achatinella ferruginea Bald. Ewa and Waianae Mts., 

 Oahu (p. 9). 



Achatinella testudinea Bald. Ewa, Oahu (p. 10). 



Subgenus CYCLAMASTRA Pilsbry & Vanatta (p. 147). 



Series of A. umbilicata; p. 149.) 

 9. A. SOLA n. sp. PI. 38, figs. 6, 9, 10. 



The shell is openly perforate, conic, thin, with but little 



