198 HELIX- AULACOSPIRA. 



b. Edentulous, spire much depressed, scarcely raised. 



mucronata. 

 bb. Aperture having teeth, spire more elevated. 



c. 1- toothed, trochiform. hololoma. 



cc. 4-toothed, spire depressed-scalariform. scalatella. 



aa. Next to the last whorl distinctly deviating, the last not carinated, 

 cylindrical ; aperture 5-toothed ; peristome not continuous, mar- 

 gins converging. Section Pseudostreptaxis. azpeitice. 



H. HOLOLOMA v. Mollendorff. PI. 54, figs. 89, 90. 



Shell narrowly umbilicated, trochiform, carinated, above sculp- 

 tured with minute very oblique riblets, the base subglabrous, 

 corneous-brown. Spire conoid, apex mamillar, slightly obtuse, shin- 

 ing ; whorls 5, convex, the last subacutely carinated, deeply sul- 

 cated above the carina, the base slightly convex ; deflexed in front. 

 Aperture extremely oblique, angulate-elliptical, the peristome thin, 

 continuous, free, expanded in every part, hardly reflexed ; columella 

 thickened, ornamented with a tooth-like nodule. 



Alt. 2, diam. 3 mill. (v. Moll.) 



Limestone cliffs of the peak of Mt. Licos, Zebu, Philippines. 



Helix hololoma v. MOELL. Jahrb. d. m. Ges., 1887, xiv, p. 275, t. 

 8, f. 12. Aulacospira (Micropetasus) hololoma v. MOELL., Landschn. 

 Cebu, p. 225. 

 H. MUCRONATA v. Mollendorff. PL 54, figs. 91, 92. 



Shell perspectively umbilicated, much depressed, discoidal ; 

 sculptured above with oblique, subdistant very minute riblets, the 

 base striatulate, subglabrous, pale horn colored. Spire very shortly 

 elevated, the apex projecting, mamillar. Whorls 4, slightly convex, 

 separated by a profound suture and a deeply excavated spiral sulcus. 

 Last whorl angulated at the periphery, flat below, shortly deflexed 

 at the aperture. Aperture extremely oblique, angulate-elliptical, 

 the peristome thin, continuous, solute, expanded in every part, 

 hardly reflexed. Alt. 1, diam. 3 mill. (Mlldff.) 



Mt. Uling and Mt. Licos, and on the west coast near Balamban 

 and Tubaran, Zebu, Philippine Islands. 



Helix mucronata v. MOELL., J. d. m. Ges. xiv, p. 276, t. 8, f. 13- 

 13b. Aulacospira (Micropetasus) mucronata v. MOELL. Landschn. 

 Cebu, p. 225. 



This species lives on nearly inaccessible limestone cliffs, in the 

 chinks and rifts of which its flat shell enables it to crawl. 



