309 Costa Rica Miocene— OlSvSOn 37 



characters of the species, the spirally striated, faint sutural sul- 

 cus and fine spiral sculpturing of the whorls. He however in 

 his notes, allies this species with the recent T. dislocata of Say, 

 which is misleading. Toula's figure can be duplicated by scores 

 of specimens in our collection. 



Tei^ebra gatunensis is characterized b}^ its large size, (length 

 50 mm or more) , its faint sutural sulcus which may be smooth 

 or with 2 or 3 faint spirals, showing best on young shells. The 

 spiral cords of the main body of the whorl are variable in num- 

 ber, spacing and strength, as well as the longitudinal ribs. A 

 large coarse variety, with persiste nt sulcus, and heavier sculp- 

 ture occurs rarely and is shown by Brown and Pilsbry as their 

 figure 2. The pillar is nearl}^ smooth, carrying a very broad 

 fold above, and a small one below. 



Gatu7i Stage: Gahm and Mt. Hope, C. Z. 



Terebra wolfgangi Toula Plate i, figure u, 12 



Terebra ivolfgangi Toula 1909, Jalirb. der K-K Geol. E.eichsand3talt, 

 vol. 58, p. 705, pi. 28, fig. 7. 



Not Terebra ivolfgangi Brown and Pils. which is T. gatunensis Toula. 



Although T. gatunensis and ivolfgangi have not been collect- 

 ed by us except in the Canal Zone, where they are abundant, 

 they are included here for the sake of completeness. It is also 

 not unlikely that future collecting ma^/ still reveal their presence 

 in the synchronous beds in Costa Rica and adjacent parts of 

 Panama. 



T. wolfgangi differs from the common T. gatunensis \iy its 

 long, tapering form, deep, persistent sulcus and a sutural band 

 generally free from spirals. It is also a much smaller species, 

 the largest specimen in our collection measuring about 38 mm in 

 length. 



Gatun Stage; Mt. Hope, C. Z. 



