104 COCHLOSTYLA-CORASIA . 



(4) GROUP OF C. THERSITES. 



Body-whorl acutely keeled in front, laterally compressed and dis- 

 torted on its latter part, not descending toward the aperture. 



C. THERSITES Broderip. PI. 21, figs. 11, 12, 13, 14. 



Imperforate, much depressed, very acutely carinated, solid; 

 whitish-yellow the apex white or purple-black, having usually four 

 dark-brown bands. Latter third or half of the body-whorl compressed 

 at the periphery, narrowing and distorting the whorl. Body-whorl 

 not descending in front. 



The surface is finely microscopically striate spirally ; whorls 4|, 

 scarcely convex, the last acutely keeled, and its latter portion much 

 compressed, not descending. Aperture very oblique, Bubtri angular ; 

 peristome thickened, white or yellowish, broadly expanded ; baso- 

 columellar margin of the lip white, adnate to the base nearly the 

 whole distance from axis to periphery. 



Alt. 15, greater diam. 32, lesser 23 mill. 



Calapan, Naujan and Baco, Mindoro, Philippines. 



H. (Carocolla} thersites BROD., P. Z. S. 1841, p. 381. PFR., 

 Monogr. i, p. 299 ; Conchyl. Cab., p. 235, t. 112, f. 3, 4. Carocolla 

 thersites Rv., Conch. Syst. ii, t. 168, f. 9. H. thersites Rv., Conch. 

 Icon., f. 126. H. (Chlorcea~) thersites HIDALGO, Obras Malacol. i, 

 p. 156, t. 23, f. 5-9. 



The laterally flattened body-whorl, not descending in front, amply 

 distinguish this from all other forms of Chlorasa. 



The dark apex and sutural line are pretty constant, although one 

 specimen before me has the apex white. The other bands are very 

 variable, some or all of them being absent occasionally. 



Section II. CORASIA Albers, 1850. 



Corasia ALB., Die Heliceen, 1850, p. 111. v. MART, in Albers, 

 Die Hel. 2d. edit., p. 170. (Type H. virgo}. PFR., Nomencl. Hel. 

 Viv., p. 199. Crystallopsis ANCEY, Couchol. Exchange, ii, p. 23, 

 August, 1887, (types H. hunteri, H. allisteri.~) 



Imperforate (rarely perforate,) depressed-globose, often carinated ; 

 thin, subdiaphanous ; whorls 335, rapidly widening, the last 

 scarcely descending ; lip slightly expanded or narrowly reflexed. 

 Surface more or less striated spirally, lacking opaque or " hydro- 

 phanous " markings. Anatomy as in Cochlostyla generally. 



