4 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.64. 



Dominican Republic ^^ ; and O. caepa Cooke from beds of upper 

 Oligocene age in Cuba.^° Cooke has fully described and figured the 

 preceding five species. Hubbard ^^ has described as 0. portoricoensis 

 casts that seem to be O. aguadillensis from beds of lower Miocene age 

 in Porto Rico and Vieques. Pilsbry ^^ has recently described as O. 

 ino'T^natiis altilh some of Gabb's specimens from the Dominican Re- 

 public that have a shorter spire than the type of O. inomatus. In 

 view of the greater difference in outline of other species the separa- 

 tion of this subspecies is hardly warranted. 0. conoides Woodring, 

 collected from beds probably of middle Oligocene age in Porto Rico, 

 completes the list of the six species that are here considered valid. 

 All the species except 0. caepa Cooke and 0. conoides Woodring 

 seem to have a stratigraphic range embracing two stages. 



Family STROMBIDAE. 

 Genus ORTHAULAX Gabb. 



Orthaulax Gabb, Acad. Nat. Sci. Philadelphia, Proc, vol. 24. p. 272, 1872. 



Type (by monotypy) : Orthaulax inomatus Gabb, Acad. Nat. Sci. Philadel- 

 phia, Proc, vol. 24, p. 272, pi. 9, figs. 3, 4, 1872. Lower Miocene, Dominican 

 Republic. 



The following is a description of the genus : 



Shell attaining a large size, fusiform, conical or ovate; cross sec- 

 tion triangular or circular; early whorls bearing varices, entirely 

 concealed in adult shells ; after 7 to 10 volutions, outer lip extending 

 to tip of spire and in each succeeding volution completely enveloping 

 spire; space between spire and each enveloping whorl filled with 

 callus ; later whorls smooth, or sculptured with narrow spiral threads 

 on and below the shoulder ; aperture elliptical, gradually constricted 

 posteriorly into a narrow channel ascending the spire; outer lip 

 thin except at posterior end of aperture, expanded, bearing near 

 the base a very shallow sinus; siphonal notch at base of aperture 

 wide and very deep; anterior fasciole swollen; base of columella 

 slender, curved backward, undercut by siphonal notch; columellar 

 callus thickened at base of posterior channel, thinner over inner lip 

 and extending to base of columella; base of body whorl of young 

 shells sculptured with spiral sulci that widen toward the base. 



»» Cooke, C. W.. U. S. Geol. Survey Prof. Paper 129-B, pp. 2-o, 31, pi. 4, figs. 5, 6 : pi. 5, 

 figs, la, lb, 1921. 



See pp. 7, 8 for additional localities in the Republic of Haiti and Cuba. 



a> Cooke, C. W., Carnegie Inst. Washington Pub. 291, p. 116, pi. 2, figs. 1, 2, 1919 (as O. 

 inomatus) ; Cooke, C. W., U. S. Geol. Survey Prof. Paper 129-B, pp. 25. 31, pi. 5, figs. 

 2a, 36, 1921. 



See p. 2 for additional localities in Cuba. 



" Hubbard, B., Scientific Survey of Porto Rico and the Virgin Islands, vol. 3, pt. 2, p. 

 146, pi. 25, figs. 1-5, New York Acad. Sci., 1921. 



^ Pilsbry, H. A., Acad. Nat. Sci. Philadelphia Proc, vol. 73, p. 369, pL 30, figs. 16-18. 

 1922. 



