55 II Costa Rica Miocene — Olsson 39 



or with two board, sub-obsolete folds. In spirifera, the two folds 

 are strong and recall those seen in the recent T. dislocata. The 

 sutural band is strongl}^ sculptured by the end of the ribs which 

 are entirely dislocated by the deep sulcus. Typical specimens 

 have three or four, even spirals, which are stronger than the 

 longitudinal ribs. Variation occurs in the number, and regu- 

 larity or these spirals, 



lycngth 43, breadth 9 mm. 



Gatun Stage: Bayiana River, Hill No. i . 

 Water Cay. 



Terebra spirifera Dall, variety mjdiensis, n. var. Plate i figure 7 



This variety, represented only by a single specimen from 

 Middle Creek, C. R., differs from typical spirifera, in having on- 

 ly three spirals, which are broad and strap-like in form. 



Gatiui Stage: Middle Creek. C. R. 

 Terebra Berlinerae Maury Plate i, figures 17, 18 



Terebra Berlmerce Maury, 1917, Eull. Amer. Pal., vol. 5, p. 19S, pi. 

 4, figs. 7, 8. 



This beautiful species was described by Dr. Maury, from the 

 Cercado (Miocene) formation of Santo Domingo. The whorls 

 are slightly convex, and its sculpture is closer, finer and more 

 delicate than is seen in anj^ of the associated Costa Rican Tere- 

 bras. Our specimens, all imperfect, were collected from the 

 hard Gatun sandstones of Boucary Creek. The most complete 

 specimen measures 21 bj^ 6.5 mm. 



Gattin Stage: Boucary Creek. 



