120 



BULLETIN 111, UNITED STATES NATIONAL MUSEUM. 



CADULUS (PLATYSCHIDES) WATSONI Dall. 



Plate 18, fig. 12. 



1881. Cadulus ivatsoni Dall, Bull. Mus. Comp. Zool., vol. 9, p. 34. 

 1889. Cadulus watsoni Dall, Bull. Mus. Comp. Zool., vol. 18, p. 429, pi. 27, fig. 12fl. 

 1898. Cadulus (Gadila) imtsoni, Pilsbry and Sharp, Tryon'eMan. Conch., vol. 17, 

 p. 167, pi. 25, fig. 50. 



The shell is slightly curved, the curvature being confined mostly 

 to its posterior portion. The convex outline describes a regular 

 arch with but little modification at the equator. The concave 

 outline is strongly arched posteriorly and straight for its remaining 

 two-thirds length, with a noticeable bulge at the equator. There is, 

 however, no localized swelling. The section of maximum diameter 

 is at about the anterior third, from which point to the larger aperture 

 the convex surface of the shell is decidedly flattened. The anterior 

 aperture is oblique and considerably compressed. The entire shell 

 is somewhat compressed except at the posterior end. The apical 

 characters which are very indistmct in the type, but are plainer in 





