309 



Costa Rica Miocene— Olsson 



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 2". dislocata of Sa}^ 

 w^hich is misleading. Toula's figure can be duplicated by scores 

 of specimens in our collection. 



Terebra gahmensis is characterized b}^ its large size, (length 

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

 or wath 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 v/ell as the longitudinal ribs. A 

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

 ture occurs rarety and is shown by Brown and Pilsbr}^ as their 

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

 fold above, and a small one below. 



Gatun Stage: Gaiun and Mt. Hope, C. Z. 



Terebra wolfgangi Toula Plate i, fioure 11, 12 



\ 



Terebra wolfgangi Toula 1909, Jaiirb. der K-K Geo!. Ileiclisandstalt, 

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



Not Terebra wolfgangi Brown and Pils. which is T. gatuneiisis 'towX's^. 



Although T. gatunensis and wolfgayigi have not been collect- 

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

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

 not unlikely that future collecting may still reveal their presence 

 in the synchronous beds in Costa Rica and adjacent parts of 

 Panama. 



T. wolfgangi differs from the common 7'. gatunensis hy 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. 



