NEW FLORIDA MOLLUSKS — BAETSCH AND EEHDER 129 



ribs. There is another broader band at the periphery of the last 

 whorl, which on the early turn is covered. Nuclear whorls 2, small, 

 strongly rounded, smooth. Postnuclear whorls almost flattened on 

 the early turns, appressed at the summit, but more rounded on the 

 later, marked b}'- slightly retractively slanting, broad axial ribs. On 

 the later whorls these have a decided hump a little anterior to the 

 middle. Of these ribs 10 occur on the first, 11 on the second and third, 

 10 on the fourth, 8 on the fifth, 9 on the sixth, and 6 on the last 

 half. The spaces separating the axial ribs are broad and shallow and 

 marked by microscopic incremental lines and equally weak spiral 

 striations. Base rather long, marked by the continuation of the 

 incremental lines and feeble spiral threads, which gain in strength 

 anteriorly and develop into 5 weak cords on the columella. Aperture 

 irregularly oval, decidedly channeled anteriorly and with a pro- 

 found sinus immediately below the summit on the outer lip, which is 

 bordered by a thick callus extending over the parietal wall as a hook. 

 Anterior to the sirius the outer lip is protracted into a clawlike ele- 

 ment bearing a feeble stromboid notch at its anterior margin. The 

 inner lip is reflected over the columella as a heavy callus, which be- 

 comes attenuated on the parietal wall. Behind the outer lip is a 

 heavy varix. 



The type, U.S.N.M. No. 493408, is one of a series of specimens 

 dredged by John B. Henderson, Jr., in 4 fathoms in Hawk Channel, 

 Fla. It has 8.5 whorls and measures: Length, 11.5 mm.; greater 

 diameter, 4.2 mm. 



We take pleasure in naming this species for Dr. George H. Clapp, 

 who accompanied Mr. Henderson on his collecting expedition. 



We also have specimens from No Name Key collected by Hemp- 

 hill, and another lot from Hawk Channel taken in 3 to 20 fathoms. 



This species is smaller and slenderer than either CerodnUia {Cero- 

 drillia) thea or C. (C.) perryae, differing also in coloration. 



LissoDRiLLiA, new subgenus 



Shell very small, elongate-turreted. Nuclear whorls 2, well rounded, 

 smooth, passing directly into the postnuclear sculpture without any 

 intermediate stage. The postnuclear whorls are appressed at the 

 summit and marked by strong axial ribs. The spiral sculpture on 

 the spire and base absent, also on the columella. Aperture de- 

 cidedly channeled anteriorly with a sinus immediately below the sum- 

 mit, which is rather deep and thickened by the reflected peristome. 

 Anterior to the notch the outer lip is produced as a clawlike element 

 and bears a feeble stromboid notch anteriorly. Inner lip reflected 

 over and appressed to the columella, extending as a callus on the 

 parietal wall. 



