30 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 125 



MORMULA COOKEI, new species 

 Plate 5, figures 2a, b 



Shell elongate-turrited, cream-yellow. The type and additional 

 four specimens before me have lost all the early whorls. Those re- 

 maining are strongly rounded and crossed by strong, protractively 

 slanting axial ribs, which are of the same strength from the summit 

 to the periphery where they terminate. Of these ribs 14 are present 

 upon the first and second whorl of the type ; 16 upon the third ; 17 upon 

 the fourth; 18 upon the fifth, and 20 upon the last turn. At irregular 

 intervals some of the ribs become fused to form a strong varix. The 

 intercostal spaces are about as wide as the ribs and are crossed by 

 seven incised spiral lines or grooves. Of these the first two below the 

 summit are very slender. While the last one immediately above the 

 periphery is very broad, the two above this are about half as strong 

 as the two above it and twice as strong as the two below the summit. 

 This arrangement, as well as the spacing, is best visualized by examin- 

 ing the sketch (pi. 5, fig. 2b). The suture is considerably constricted. 

 The periphery is well rounded. The base is short, hemispherical, and 

 without sculpture. The aperture is subquadrate; the columella is 

 slender, vertical, slightly revolute and provided with a feeble fold at 

 its insertion; the parietal wall is glazed by a thin callus; the outer 

 lip is thin and bears four strong spiral cords within. 



The type, U.S.N.M. No. 561683, comes from the PHocene of North 

 St. Petersburg, Fla. It has 6.2 whorls remaining which measure: 

 Length, 5.9 mm., diameter 2.0 mm. U.S.N.M. No. 561684 contains 

 two additional specimens from the same source, and two more are 

 in the collection of the A.N.S.P. 



The very strongly rounded whorls readily distinguish this species 

 from the other Mormulas. 



It is a pleasure to name this species for Dr. C. Wythe Cooke, of 

 the United States Geological Survey, who has devoted a lifetime of 

 energy to the unraveling and elucidation of southeastern United States 

 geology and paleontology. 



MORMULA WOODRINGI, new species 



Plate 4, figures 8a, b 



Shell elongate-turrited, cream-yellow. The early whorls are lost 

 in the unique type; those remaining are moderately rounded and 

 crossed by strong, protractively slanting, rather distantly spaced axial 

 ribs, which are of the same strength from the summit to the periphery 



