ABT.l. TERTIARY MOLLUSKS FROM THE WEST INDIES WOODRING. 9 



of Rio Yaqiie del Sur at upper edge of Los Giiiros, Dominican Re- 

 public, D. D. Condit, collector, 1919, five specimens, U.S.G.S. sta- 

 tion 8572, Lower Miocene, west bank of Rio Yaque del Sur opposite 

 Palo Copado, Dominican Republic, D. D. Condit, collector, 1919, one 

 specimen, U.S.G.S. station 8590. Lower Miocene, trail from Azua 

 to Cabral, about 10 kilometers west of crossing of Rio Tabara, 

 Dominican Republic, N. H. Darton, collector, 1920, one specimen, 

 U.S.G.S. station 8760. 



ORTHAULAX CONOIDES, new species. 



Plate 2, figs. 1, 2, 7. 



Shell medium sized, conical, spire low, the enveloping whorls bent 

 almost at an angle of 90° at the shoulder: cross section circular; 

 callus between the whorls lenticular below the shoulder, abruptly 

 thinning above the shoulder and continuing as a very thin wedge 

 to the apex of the shell ; upper edge of body cavity angular on later 

 whorls, more rounded on early whorls ; aperture not known. 



The dimensions in millimeters are given in the following table : 



Height. Diameter. 



45-f- 53 (type, pi. 2, tigs. 2, 7) 



53-H 47 (pi. 2, fig. 1) 



52+ 47 



25-f 43 



Type.—Q^i. No. 328395, U.S.N.M. 



Type, locality, — U.S.G.S. station 1/139, Porto Rico, Province of 

 Aguadilla, pit No. 5, on right side of Rio Guajataca at dam site, 

 from upper and harder layers of " lower limestone," altitude about 

 192 meters above sea level, G. R. Mansfield, collector, February 8, 

 1922, type and eight other specimens, four of which are casts. 



The remarkable conical outline of the shell separates this species 

 from all the described species of Orthaulax. A large specimen of 

 O. gabhi in the collections of the United States National Museum 

 from Alum Bluff, Florida (U.S.G.S. station 2211), has an unusually 

 low spire and abruptly angulated shoulder, simulating the outline 

 of O. conoides. The callus of 0. conoides is more evenly lenticular 

 below the shoulder than in O. gabhi^ resembling 0. aguadillensis^ 

 from which it differs in the abrupt constriction above the shoulder. 

 As the body cavities of 0. conoides and 0. agiiadillensis are similar, 

 casts of the two species are virtually indistinguishable, although O. 

 conoides does not reach the large size of O. aguadillensis. All the 

 specimens of O. conoides are imperfect. They were embedded in 

 limestone, but the shell and callus are preserved or faithfully re- 

 placed by calcite. 



