36 Bulletin 39 308 



Terebra bipartita Gabb, 1873, Trans. Amer. Phil. Soc, vol. 15, p. 

 225. 



Terebra {Acus) bipartita Dall, 1895, Proc. U. S. Nat. Mus. , vol. 18, 

 p. 38. 



Terebra bipaHita Maury, 1917, Bull. Amer. Pal., vol. 5, p. 187, pi. 3 

 fig. 14. 



This species, possessing much the same type of sculpture as 

 S7dcife7'a, subsulcifera, haitensis &ic., is recognized by having two, 

 instead of one columellar plication. Full-grown specimens 

 have a bipartite .sculpture while in sulcifera and the others it is 

 tripartite. 



The Costa Rican collection contains three specimens from 

 Saury creek, near Cahuita, the largest of 10 incomplete whorls 

 mearures 77 by 19 mm. 



Gatun Stage: Zone E. Saury Creek 



Terebra gatunensis Toula Plate i, figures 4-6 



Terebra gatunensis Toula, 1909, Jahrb. der K-K Geol. Reichsanstalt, 

 vol. 58, p. 705, pi. 25, fig. 14. 



Terebra gatunensis Brown and Pilsbry, 191 1, Proc. Acad. Nat. Sci. 

 Phil., vol. 63, p. 339, pi. 22, fig. 2. 



Terebra wolfgangi Brown and Pilsbry, 191 1, Proc. Acad. Nat. Sci. 

 Phil., vol. 63, p. 340, pi. 22, figs. I, 3-6, but not of Toula, 1908. 



Terebra {Myurella) gatunensis Cossman, 1913, Jour, de Conchyliologie, 

 vol. 61, p. 13, pi. I, figs. 26-29. 



In the Canal Zone, the Gatun beds contain two common 

 species of Terebra, which were described by Toula as gatun- 

 ensis and wolfgangi. These species have been more or less con- 

 fused by Brown and Pilsbry, so that their figures and description 

 of wolfgangi, really represent gatunensis . Their figure 2 is a 

 large and less common variety oi gatunensis. Toula' s figure, al- 

 though of a young imperfect shell, is clear and shows the main 



