Aivr. 22 MIOCENE GASTROPODS AND SCAPHOPODS MANSFIELD 53 



them. A similar type of shell occurs at station 5853, Panam'a Canal 

 Zone, apparently from the Culebra formation. 



Locality of figured specimen: 9220, Naxiva County, Charuma 

 Ward, Machapoorie Quarry, Trinidad. 



OcGUfTence. — Lower Miocene : 8299, Caroni County, San Rafael 

 Ward. Cumuto Road, 17 miles from Eastern Main Road. 



TURRITELLA CAPARONIS Maury 



Plate 9, figs. 10, 11 



Turritella caparonis Maury, Bull. Amer. Paleont., vol. 10, no. 42, p. 234, pi. 42, 

 figs. 1, 2, 1925. 



Shell strong, acute-conic, of eighteen whorls (estimated) ; nucleus 

 decollate; whorls slightly convex in outline; sutural area shallow, 

 roundly concave; suture close-fitting, distinct on earlier whorls and 

 p)artly concealed on the later whorls by the preceding spiral ridge. 

 Sculpture mainly of four equally spaced primary spirals of equal 

 strength, save the presutural one, which is weaker, being lower-lying, 

 rounded, finely spirally marked and projecting over the suture. The 

 three other primary spirals begin on the earliest whorls as distinct, 

 weakly beaded, fine, raised cords, but in ascending the whorl these 

 gradually become more prominent, consisting of high, thin, denticu- 

 lated, erect ridges, resembling the threads on 'a screw, the forward 

 third forming the periphery of the whorl. Another beaded spiral 

 lies near the upper base of the posterior ridge, faint on the early 

 whorls but gradually increasing in strength in ascending the whorl. 

 On the later whorls, a much finer spiral thread lies shortly below the 

 suture. Weak, arcu'ate growth threads cross the spiral interspaces. 



Dimensions: Synthesis of two specimens (U. S. Nat. Mus. Cat. No. 

 352681) measures: Length 28 mm.; greatest diameter 16 mm. 



The species resembles Tui^Htella chiqyolana Dall, from the Chipola 

 marl member of the Alum Bluff formation, Florida. The species 

 has four spirals on the earliest whorl, the Chipola species has three, 

 and has much higher and thinner spiral ridges than the Chipola 

 form. 



Occur-rence. — Lower Miocene: Station 8301 (loc. 5, F. W. P.). 

 Nariva Count3^ Charuma Ward, Machapoorie Quarry. 



TURRITELLA MONTSERRATENSIS. new species 



Plate 9, figs. 5, 6 



Turritella altilira var. to7-nata Maury (part), Bull. Amer. Paleont., vol. 10, 

 No. 42, p. 230, pi. 42, fig. 3, 1925. (Not Turritella tornata Guppy.) 



The cotypes consist of the lower five whorls of an adult specimen 

 and the lower three whorls of a young specimen, the nuclei of both are 



