Maryland Geological Survey 413 



initial turn and a half largely submerged in the succeeding volution ; 

 external sculpture reticulate, the axial coste evanescing on the base of the 

 body ; aperture holostomous, outer lip thin, sharp, broadly arcuate ; inner 

 lip deeply excavated at the base of the body ; columella non-plicate ; ante- 

 rior extremity of the aperture bent slightly forward and constricted to 

 form an incipient canal; parietal wall washed with callous; umbilicus 

 closed but indicated by a feeble depression behind the reverted labium. 



This genus differs from Trichotropis, to which the type species has been 

 commonly referred, in the nuclear characters, the general contour of the 

 shell and the closed umbilicus. The protoconch is similar to that of Can- 

 cellaria, but the absence of any trace of columellar plications excludes 

 the form from the typical section of the genus. It differs from Admete 

 in the peculiar forward twist of the anterior portion of the aperture and 

 the less clearly indicated anterior canal. Admete has not been reported 

 from strata lower than the Pliocene, and though the genera are apparently 

 closely related, it seems better to keep them distinct until further material 

 makes their closer relationship more obvious. 



Paladmete cancellaeia (Conrad) 

 Plate XVIII, Pigs. 14, 15 



Trichotropis cancellaria Conrad, 1858, Jour. Acad. Nat. Sci., Phila., 2d ser., 

 vol. iii, p. 333, pi. xxxv, fig. 8. 



Description. — " Acutely subovate ; volutions five; spire subscalarif orm ; 

 body whorl ventricose; longitudinal ribs narrow, prominent, distant; 

 revolving lines prominent, distant, with an occasional minute inter- 

 mediate line ; columella profoundly incurved ; labium reflected ; base sub- 

 umbilicated ; shoulder of body volution with minute revolving lines, and 

 one larger than the others." — Conrad, 1858. 



Type Locality. — Owl Creek, Tippah County, Mississippi. 



Shell small, nassoid in outline, spire a little higher than the aperture ; 

 whorls seven in number, the earlier turns increasing regularly in size, 

 broadly convex, the later tabulated posteriorly; nuclear turns approxi- 

 mately three in number, the initial whorl and a half very small and largely 

 immersed in the succeeding volution, the final nuclear turn relatively 

 27 



