PROCEEDINGS OF THE UNITED STATES NATIONAL MUSEUM 



issued H^?(VA, 0?Mi hy the 



SMITHSONIAN INSTITUTION 

 U. S. NATIONAL MUSEUM 



Vol. 87 Washington: 1939 No. 3070 



NEW TURRITID MOLLUSKS FROJ^I FLORIDA 



By Paul. Baetsch and Hakald A. Rehder 



A RECENT sending of a lot of turritid mollusks by Dr. Louise M. 

 Perry, of Sanibel Island, Fla., has made it necessary to put on record 

 some new superspecific groups, as well as species, which are here 

 defined. 



CERODRILLIA, new genus 



Small, elongate-turreted shells having a waxy appearance with the 

 nuclear whorls smooth, passing directly into the postnuclear sculpture 

 without intermediate stages. The whorls are provided with strong 

 axial ribs. The spiral sculpture varies as indicated in the two sub- 

 genera described below. Aperture with a short anterior channel ; outer 

 lip with a deep sinus immediately below the summit and a stromboid 

 notch near the anterior margin. 



Type : CerodriUia clappi^ new species. 



"We are recognizing two subgenera of this genus, which the follow- 

 ing key will help to differentiate : 



KEY TO THE SUBGENERA OF CERODRILLIA 



Shell with spiral sculpture on base and columella CerodriUia 



Shell without spiral sculpture on base and columella Lissodrillia 



CERODRILLIA, new subgenus 



Small shells of elongate-turreted outline. Nuclear whorls smooth, 



passing directly into the postnuclear sculpture without intermediate 



stages. Postnuclear whorls appressed at the summit, marked by 



prominent, retractively slanting, somewhat sigmoid axial ribs, which 



155191—39 127 



