AURICULELLA, MOLOKAI. 101 



Tornatellina kusteri PPR., Proc. Zool. Soe. Lond., 1854, p. 

 295 ; Monographia Hel. Viv., iv, p. 650. 



A species not recognized by subsequent authors, which by 

 its assigned size, color and apertural characters seems to be 

 an Oahuaii Auriculella. It is probably identical with some 

 known species. 



Group of A. cerea. 



The shell is umbilicate, perforate or imperforate, from 

 broadly ovate to attenuate, thin or solid. The colurnella is 

 usually edentulous, rarely minutely dentate; but without a 

 lamella at any stage of growth. Lip slightly thickened to 

 strongly thickened. No palatal plicae at any stage. In the 

 young the shell is imperforate, angled, the lip thin. Colu- 

 mella twisted, usually with a minute, very oblique fold. 



This group includes the shells from Molokai, Maui, Lanai 

 and Hawaii. The very oblique minute columellar fold is con- 

 stant in the young of all the species examined, but there is no 

 superposed lamella. 



Species of Molokai. 

 a. Shell rather thin. 



b. Parietal callus thin throughout. 



c. Length about 7 mm., with 7 whorls. 



A. newcotnbi, no. 20. 



c 1 . Length about 5.5 to 6.5 mm. ; yellow, 6 to 6% 

 whorls. A. flavida, no. 21. 



6 1 . Parietal callus thick at the edge. 



c. 1 Length about 5.5 to 6.5 mm., 6 to 6% whorls. 



A. flavida, no. 21. 

 c 1 . Length about 8.5 mm., with 8 whorls. 



A. cerea, no. 22. 

 a 1 . Shell decidedly solid, rather thick. 



&. Imperforate, the columella not built forward ; in ob- 

 lique view very indistinctly bidentate deep within. 



A. canalifera, 110. 24. 



ft 1 . Imperforate or umbilicate, the columella built for- 

 ward in adults; in oblique view having an obtuse 

 fold deep within. A. brunnea, no. 23. 



