6LAVATOR. 193 



truncate. The soft anatomy is unknown. Type C. obtusatus 

 Gmel. 



Distribution, Madagascar. 



The species are illustrated on plates 48-51. 



This group of handsome snails will probably be largely 

 increased as Madagascar is further explored. The species 

 resemble several diverse groups in other regions. C. obtusatus 

 has a Stenogyroid contour, C. grandidieri is Placostyloid, 

 and C. balstoni, eximia etc. recall Thaumastus. 



The relation of Clavator to other genera cannot be intelli- 

 gently discussed until the soft parts are investigated. Fischer 

 (Manuel) placed the group under Bulimus, but nearly all 

 other authors have considered it to be Stenogyroid. Be- 

 sides the following species, Obeliscus sceptrum Beck, Index 

 Moll. p. 61, a nude name, pertains to this group. 



Key to Species. 



1. Columellar lip built forward above the umbilical fissure 

 which is thus left uncovered; peristome more or lew 

 thickened, obtuse ; shell conspicuously striped with chest- 

 nut on a yellow ground. 



a. Shell slender, attenuated above, the diam. less than 

 one-third the length, rib-striate, whorls about 10. 



C. obtusatus, no. 2. 



aa. Shell large, stout, Placostylus-like, the diam. usually 

 much exceeding a third of the length; spire conic; 

 last whorl smoothish, arcuately plicate at the suture ; 

 whorls about 8. C. grandidieri, no. 1. 



2. Columellar lip reflexed over and nearly or quite closing 

 the umbilical fissure, sometimes also thickened. Colors 

 less strongly contrasting. 



a. Diameter of shell less than one-third its length. 



b. Spire slender and attenuate above; peristome but 

 slightly or not thickened; whorls 9 to 10. 

 c. Lower whorls narrowly streaked with dark 

 chestnut, sometimes wavy or mottled. 

 d. Length 52 to 60 mm. C. moreleti, no. 4. 

 dd. Length 80-95 mm. C. humbloti, no. 5. 



