STROMBID^E. 103 



is ribbed longitudinally, occasionally varicose, and without pos- 

 terior canal. R. crucis, Bay an. 



Section CYCLOMOLOPS, Gabb, 1868. Eocene. S. and S. Conch., 

 ii, 192, t. 60, f. 77. 



Subgenus HIPPOCHRENES, Montfort, 1810. 



Eocene of Europe and America. S. and S. Conch., ii, 191, t. 

 60, f. 75. 



Section ORTHAULAX, Gabb, 1873. Tertiary. S. and S. Conch., 

 ii, 192. 



Section LEIORHINUS, Gabb, 1860. Eocene, Ala. S. and S. 

 Conch., ii, 191, t. 60, f. 92. 



Section CALYPTROPHORUS, Conrad, 1857. Eocene, U.S.; Cre- 

 taceous, India. S. and S. Conch., ii, 192, t. 60, f. 78. 



Subgenus PTERODONTA, d'Orbigny, 1851. 

 Cretaceous. S. and S. Conchology, ii, 190, t, 88, f. 56. 



Genus TEREBELLUM, Klein, 1753. 



Anterior part of foot very small, posterior part oval, com- 

 pressed ; eyes on the ends of peduncles; no tentacles; siphon 

 rudimentary; mantle with a posterior filiform appendage, laying 

 in the sutural canal. Operculum small, narrow, digitated. 



Shell elongate, subcylindrical, spire rather short, apex obtuse; 

 aperture narrow, broadly notched in front ; lip simple, columella 

 truncated. 



Section I. TEREBELLUM (sensu stricto). Shell smooth, spire 

 rather short, with channeled suture. T. xubulatum^ Linn. 



Section II. TEREBELLOPSIS, Leyraerie, 1844. Nummulitic. S. 

 and S. Conch., ii, 193, t. 60, f. 81. 



Section III. SERAPHS, Montfort, 1810. Spire concealed under 

 a callous covering. Eocene. T. convolutum, Lam. 



Section IV. MAURYNA, Gregorio, 1880. Surface longitudinally 

 folded. Nummulitic. T. plicatum, d'Arch. 



Subfamily Aporrhainas. 

 Genus APORRHA1S, Dillwyn, 1823. 



Shell fusiform, spire turreted, with a short canal in front, and 

 a posterior canal running up the spire ; outer lip of adult expanded, 



