118 BULIMELLA. 



Apex VON MARTENS, Die Heliceen, 1860, p. 248, type Achati- 

 nella lugubris Chemn. 



Shell imperforate or minutely perforate, oblong, ovate or 

 globose-conic, smooth or longitudinally corrugated, with only 

 minute and weak traces of spiral sculpture; color in spiral 

 bands or streaks in the direction of growth-lines, never in 

 forwardly-descending stripes; lip simple or thickened within, 

 sometimes slightly expanding ; columella bearing a strong cal- 

 lous fold. 



Type A. apexfulva (Dixon). Distribution, the island of 

 Oahu. Living on the leaves and limbs of trees and bushes. 



Data on the soft anatomy, distribution, etc., of Achatinella 

 may be found in the Introduction of this volume. 



Achatinella was early divided into several subgenera or sec- 

 tions, but their contents as seen in the lists in Die Heliceen^ 

 Nomenclator Heliceorum Viventium and other works were 

 rather heterogeneous. Gulick and Baldwin grouped the 

 species more naturally, practically limiting the groups as in 

 this work. Three sections or subgenera are recognized. There 

 are a few species on the border between Bulimella and Acha- 

 tinellastrum, but otherwise the sections are. quite distinct, 

 though they can scarcely be rigidly diagnosed. 



Sections of Achatinella. 



Bulimella Pfr. Outer lip thickened by a strong callous rib 

 within; shape oblong-conic or ovate; summit obtuse, rounded 

 or convexly-conic. 



Achatinellastrum Pfr. Outer lip thin or a little thickened 

 within, not expanded ; early whorls not conspicuously flat- 

 tened, the summit conic, not very obtuse. 



Achatinella s. sir. Outer lip well thickened within, scarcely 

 or not expanded ; shape globose-conic or ovate-conic, the sum- 

 mit conic, embryonic whorls flattened. 



Section BULIMELLA Pfeiffer. 



Bulimella PFR., Malakozoologische Blatter, i, 1854, p. 119. 

 MARTENS, Die Heliceen, 1860, p. 244, type A. rugosa Newc. 



Achatinellse with the shell ovate-conic or somewhat pyra- 



