263 



Costa Rico Miocknk — OlSvSon 



91 



ly related if not identical form, was collected b}^ us from the 

 Pleistocene at Almirante, Panama, and several broken specimens 

 from the beaches at Bocas del Toro, Panama, and from. Manzan- 

 illa, C. R. This recent Atlantic form differs only from the typ- 

 ical V\^est Coast testacea in being somewhat more slender and ap- 

 parently differently colored. 



Try on in the Manual of Conchology unites testacea with 

 hiatula Gmelin from West Africa. 



Gatun Stage: Bana^ia River ^ Coll, <5, of Red Cliff 

 Creek, C R. 



Oliva mancinella, n. sp. Plate 7, figures 8, 9 



Shell slender and more delicate than the preceding; spire 

 long and pointed and about 1-3 of the total length of the shell; 5 

 whorls; sutures deep; the spire- whorls have their lower half 

 thickened by a smooth, encircling band of callus; aperture broad- 

 est about the lower half; inner lip smooth above, with only a 

 small and weak callus at its junction with the outer lip; the out- 

 er lip carries below, 3 or 4 heav}' and very oblique plaite; the 

 outer lip is smooth and sharp. 



Ivength48, diameter 11 mm. 



This species differs from O. testacea and its variet}^ costariceii- 

 sis by its much more slender and delicate shell. The porpor- 

 tions of the spire are about 1-3 of the total length of the shell. 



Gatun Stage: Coll. 4., East Grape Poiyit, Creek, C. R. 



Genus OLfVELLA Swainson 



A. Shell large, length 20 mm. or more; spire long and about 

 ^2 the total length of the shell. 



OUvella goliath, n. sp. 

 A A. Shell smaller; spire long or short, usually less than % 

 of the total length. 



B. Shell short and stubby, spire rather short. 



