T. HKTIJHX BEILUS -Pilsbry, 1SSS. j>l. ()). |j 



Shdl subimperforate, turbinate-conic, solid, soiled 

 longitudinally (lammulate with greenish and brown, Iase irr. -.ular- 

 ly maculated with the same colors; sculpture consisting of spiral 

 lira- cut into regular close rounded beads; the interstices hetv 

 ihc principal line occupied by beaded liriihc, or, on : the upper 

 whorls by very close regular small folds, in the direction of 

 incremental lines, the surfaces of which show traces of microscopic 

 impressed spiral lines; the line number about 20 on the last whorl ; 

 three or four about the peripheral region are more prominent: t 

 of the base are subequal. and less conspicuous; the sculpture aU. 

 becomes obsolescent toward the termination of the last whorl ; spire 

 conic, acute, small; sutures subcaiialiculate, with a beaded border; 

 whorls o-l 6, quite convex, rapidly increasing, the last large, con- 

 vex, slightly descending anteriorly; aperture about half the total 

 altitude of shell, oblique, oval, rounded above and below, silvery 

 within, the outer lip acute, rather thin, regularly arcuate, the col- 

 umellar callous continued upon the parietal wall, forming a ; 

 larly arcuate inner lip ; parietal callus dilated upon the body-whorl 

 in front of the aperture; columella rounded, the lip slightly ev 

 partly covering the umbilical fissure, which is encircled by a spiral 

 ridge terminating at the base of the columella. 



Alt. :;."), diam.33 mill. 



ir<ibitnl mil:' 



This handsome Sen-cctus is more closely allied to T. filosns than to 

 any other known species. The general form and proportions arc 

 the same, but the beautifully beaded line and especially the almost 

 perfectly oval aperture will separate it from that species. In color, 

 too, the forms are diverse. /Ihe parietal callus is not shaped like 

 that of T.filosus, nor is the columella below so broadly everted and 

 lipped as in that species. Tlie anterior outline of the callus, from 

 the base to the superior angle of the aperture, is wholly different in 

 the two species. The sculpture and columella will separate this 

 form from T. spen'/ferianus, which, with heterocheilu9 and fi 

 form a group of species, lying on the outskirts of Senectut, the more 

 prominent characters of which are found in the peculiar parietal 

 callus and the operculum which exhibits a feebly spiral structure 

 outside. 

 14 



