TURBO. 209 



T. HETEROCHEiLus Pilsbiy, 1888. PL 69, figs. 22, 23. 



Shell subimperforate, turbinate-conic, solid, soiled white, above 

 longitudinally flammulate with greenish and brown, base irregular- 

 ly maculated with the same colors ; sculpture consisting of spiral 

 lirte cut into regular close rounded beads ; the interstices between 

 the principal lirse occupied by beaded lirulre, 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 lirse number about 20 on the last whorl ; 

 three or four about the peripheral region are more prominent; those 

 of the base are subequal, and less conspicuous ; the sculpture also 

 becomes obsolescent toward the termination of the last whorl; spire 

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

 whorls 5o-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 regu- 

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

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

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

 ridge terminating at the base of the columella. 

 Alt. 35, diam. 33 mill. 



Hahitat unJcnotvn. 



This handsome Senedus is more closely allied to T. Jilosus than to 

 any other known species. The general form and proportions are 

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

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

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

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

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

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

 the two species. The sculpture and columella will separate this 

 form from T. spencjlerianus, w^hich, with heterodiellas and jilosus 

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

 prominent characters of which are found in the peculiar parietal 

 callus and the operculum Avhich exhil)its a feebly spiral structure 

 outside. 

 14 



