270 American Seashells 



1 5 short axial ribs per whorl. Spiral threads numerous and fine. Sinus small, 

 its posterior end round, its opening narrow. Not uncommon below low 

 water under rocks. 



C. sanibelensis Bartsch and Rehder is similar, but i inch in length, with 

 9 longer and wider axial ribs, with a large slit, and colored orange-chestnut 

 with white between the ribs. Uncommon around Sanibel Island. 



Subgenus Crassispirella Bartsch and Rehder 1939 

 Crassispira ostrearum Stearns Oyster Turret 



Plate 26n 



North Carolina to south half of Florida. Cuba. 



% to % inch in length; light yellow-brown to chestnut. Sinus U-shaped. 

 About 20 weakly beaded axial ribs per whorl. Just below the suture there 

 is a single, smooth, strong spiral cord. Spiral threads moderately strong to 

 weak (16 to 20 on the last whorl, 4 between sutures). Lower part of outer 

 lip thin and strongly crenulate or wavy. Common from low water to 90 

 fathoms. C. tampaensis Bartsch and Rehder is very similar, and may be this 

 species. 



Genus Cerodrillia Bartsch and Rehder 1939 

 Cerodrillia perry ae Bartsch and Rehder Perry's Drillia 



West coast of Florida. 



/4 inch in length, flesh-colored, with a broad, golden-brown band 

 around the periphery. 8 to 9 axial ribs per whorl. Faint spiral lines present. 

 Not uncommon. C. tbea has shorter axial ribs and is uniform chocolate- 

 brown. 



Cerodrillia thea Dall Thea DriUia 



Figure 57f 



West coast of Florida. 



!4 inch in length, thick-shelled, with a glossy-brown finish, and with 

 the short, slanting ribs cream in color. Outer lip prominent. Sinus deep 

 and U-shaped. Uncommon in shallow water. 



Genus Monilispira Bartsch and Rehder 1939 

 Momlispira albinodata Reeve White-banded Drillia 



Southeast Florida and the West Indies. 



V2 inch in length, resembling a Cerithimn in shape; color dark blackish 



