COCHLOSTYLA-ORTHOSTYLUS. 199 



(1) Typical species of Orthostylus. 



C. BICOLORATA Lea. PI. 44, figs. 40, 41. 



Imperforate, pyramidal, solid ; ground-color chestnut above, green 

 below the periphery. Covered with a brown hydrophanous cuticle 

 which is streaked obliquely with lighter, and is varied by a creamy 

 band near the periphery, a series of alternating light and denuded 

 dark blotches below the suture followed by another band, and frequently 

 a third band on the base. 



The spire is notably pyramidal and elevated, apex rather obtuse. 

 Whorls 6*. Aperture small, oblique, white inside ; peristome dark 

 chestnut colored, broadly expanded and reflexed. Columella 

 vertical, obliquely truncated beneath, brownish. 



Alt. 60, diam. 38 mill. 



Alt. 63, diam. 42 mill. 



Lucban, Prov. Tayabas, Luzon ; Boac and Gasan, Marinduque ; 

 A labat, Philippines. 



Bui. bicoloratus LEA, Proc. Amer. Philos. Soc., p. 173, 1840; 

 Trans. Amer. Philos. Soc. vii, p. 459, t. 11, f. 8, 1841. EVE., Conch. 

 Icon., f. 22. Cochlostyla bicolorata MLLDFF. Nachr. D. M. Ges. 

 1889, p. W4.Bul. alberti BROD., P. Z. S. 1841, p. 35. PFR., 

 Monogr. ii, p. 3 ; Conchyl. Cab. Bui., t. 50, f. 3. Cochlostyla alberti 

 SEMP., Reisen, p. 202. HIDALGO, Journ. de Conch. 1887, p. 163 ; 

 Obras, t. 65, f. 2, 3. Bulinus onyx BROD., P. Z. S. 1841, p. 34.- 

 Bnlimus onyx PFR., Monogr. ii, p. 32. Cochlostyla alberti var.onyx 

 HIDALGO, Obras, Malacol. i, t. 65, f. 4, 5. 



The ground-color is peculiar, being green below, chestnut-brown 

 above the periphery. When quite denuded, the green color, being 

 epidermal, disappears, white replacing it. There is sometimes a 

 broad chestnut band beneath, conspicuously modifying the green 

 color, and leaving green bands only at periphery and columella. 



Var. ONYX Brod. PI. 61, fig. 22. 



More elongated and with the last whorl notably narrower. 

 Alt. 60, diam. 27 mill. ; apert., alt. 29, diam. (inside) 1 6 mill. 



Luzon. 



C. IMPERATOR Pfeiffer. PI. 45, figs. 42, 43, 44. 



Imperforate, pyramidal, solid. Ground-color brown-black on the 

 body- whorl, light brown on the two preceding whorls, the earlier 



