128 PKOCEEDINGS OF THE NATIONAL MUSEUM vol.87 



extend from the summit to the columella, where they evanesce. The 

 entire surface of the shell is marked by scarcely perceptible incremental 

 lines and equally faint spiral striations; the latter change into feeble 

 threads on the base and columella, being stronger on the latter. Aper- 

 ture irregularly oval, decidedly channeled anteriorly ; outer lip with a 

 deep sinus immediately below the summit, separated from this only by 

 the thickened peristome. Anterior to the sinus the shell is protracted 

 into a clawlike element. There is a feeble stromboid notch at the ante- 

 rior end of the outer lip ; the inner lip is reflected over the columella as 

 a heavy callus, which extends in varying degi-ees over the parietal wall. 

 Type: CerodrilUa {GerodrilUa) clappi, new species. 



CERODRILLIA (CERODRILLIA) PERRYAE, new species 

 Pr.ATE 17, FiGUKE 1 



Shell elongate-turreted, flesh-colored, ^^ith a broad golden-brown 

 band, which extends from the middle of the turns to a little beyond the 

 periphery. Nuclear whorls 2, strongly rounded, smooth. Postnuclear 

 whorls moderately rounded, marked by strong, distantly spaced, broad 

 axial ribs, which on the early whorls attain their greatest development 

 at the periphery ; in the later whorls the hump is a little anterior to the 

 middle. Of these ribs, nine occur on the first, second, and third, eight 

 on the fourth and fifth, and two on the last quarter of a turn. The 

 spaces separating these ribs are broad and shallow and marked by 

 microscopic incremental lines and equally faint spiral striations. Pe- 

 riphery well rounded, the axial ribs evanescing at the periphery. Base 

 moderately long, marked by feeble spiral threads which increase in 

 length from the periphery anteriorly and develop into five equal and 

 almost equally spaced cords on the columella. Outer lip of the type, 

 which is not quite mature, since it has not yet developed the deep notch, 

 but merely a shallow sinus anterior to the summit, protracted ante- 

 riorly to the sinus and backed hy a heavy varix. Anterior channel 

 profound; inner lip reflected over the columella as a callus which 

 extends up on the parietal wall. 



The type, U.S.N.xM. No. 508644, was collected by Dr. Perry at Sanibel 

 Island. It has 8.2 whorls and measures : Length, 12.9 mm. ; greater 

 diameter, 5.3 mm. 



CerodrilUa {CerodriUia) thca (Dall) difl:ei*s from this species in 

 being of a uniform chocolate-broAvn color and in having the axial ribs 

 shorter and broader, the knobs more pronounced. 



CERODRILLIA (CERODRILLIA) CLATPI, new species 

 Plate 17, Figxjke 4 



Shell small, elongate-turreted, yellowish white, wath a faint pale- 

 brown band a little anterior to tlie broadest expansion of the axial 



