COCHLOSTYLA-HELICOSTYLA. 181 



widely expanded and reflexed, the outer margin sinuous ; columella 

 rather straightened, excavated above, dilated, appressed. (Moll.') 



Alt. 50, greater diam. 46, lesser 36 mill. ; aperture (with perist.) 

 36 mill, long, 31 wide. 



High mts. on the boundary between the provinces Bulacan, Manilla 

 and Morong. 



C. (Helicostyla) boettgeriana v. MOLL., Nachr. D. M. Ges. 1888, 

 p. 101. 



Belongs to the group of C. mirabilis Fer. The acute conic spire, 

 the broad dull white crenulated suture, the strong, almost fold-like 

 oblique wrinkles, separate it from all species known to me. (Moll.) 



Subsection 4. HELICOSTYLA Fer., 1819. 



Helicostyla FER., Prodr. p. 46 (in part). 



This section serves to contain the oblong or globose-conic species 

 remaining after the segregation of the various allied groups. It is 

 consequently rather miscellaneous as to contents and characters, 

 but perhaps less so than in previous works, where it has been made 

 still more comprehensive. 



(1.) Group of C. mirabilis. 



C. MIRABILIS Ferussac. PL 57, figs. 79-86 ; pi. 31, fig. 40. 



Imperforate, rather solid, globose; ground-color unicolored yellow 

 or brownish-yellow, without bands, or variously banded with brown 

 or black-brown, the bands when present being all of nearly the same 

 color, and generally 4 in number; a narrow sutural line, two wider 

 zones girdling the middle part, and a columellar patch. 



Surface nearly smooth, lightly striatulate. Bands wide, narrow 

 or none, and when present either blackish-brown or reddish-brown 

 in color. Whorls nearly 5, the last but little descending in front. 

 Aperture oblique, white inside and showing the bands ; lip broadly 

 reflexed, white, its reverse usually snow-white also ; columella sub- 

 vertical, gently arcuate, very deeply inserted, and visibly twisted 

 near the insertion. 



Alt. 36, diam. 34 mill, (average specimen.) 



Alt. 40, diam. 29 mill, (elongated specimen.) 



Alt. 30, diam. 32 mill, (short specimen.) 



Southeastern and middle Luzon; Islet of Alabat, off E. coast 

 Mauban ; Marinduque, Philippines. 



