4^1 



Costa Rica Miocene — Olsson 



249 



more convex than t5'pical C. grus from the Carolinas and more 

 finely sculptured. More material is needed to show whether or 

 not these charaters are constant. The C. grus appears as a 

 fossil in the Upper Chesapeake Miocene of the eastern United 

 States and is recent from Cape Hatteras to Yucatan. 

 Gatun Stage: Coll. Red Cliff creek. 



Genus TELLINA, (Linne) Lamarck 

 Teilina rovala, n. sp. Plate 26, figures 7, 8 



Shell elongate, slender, subequilateral with the beaks situ- 

 ated near the center of the shell; anterior side long, with a 

 straight dorsal margin and narrowly rounded at its extremity; 

 posterior side much narrowed and rostrate, the left valve with 2 

 radial bands forming the rostrum, the dorsal one a fold, the oth- 

 er a wide sinus; ventral margin rounded anteriorly, nearly 

 straight about the middle and a wide sinus posteriorly; the sur- 

 face is sculptured with even, concentric lamellae; this sculpture 

 on the rostrum is heavier and on crossing the fold and sinus be- 

 come reversed in position. 



Length 29, height 12, semi-diameter 2.5 mm. 

 36? 14 3 mm. 



We have two specimens of this tj^pical Teilina from Water 

 Ca}^. The larger specimen is fragmentary but probably measur- 

 ed when complete about 36 mm in length. The species recalls 

 the recent West Indian T. interrupta Wood (7". antonii Y\^\Xv^y^) 

 in its form and sculpture but lacks the finer radiating striae. 



Gatun Stage: Water Cay. 



Subgenus ARCOPAOIA, (Teach) 



Section IVIERISCA, Ball 

 Teilina crystalHna Wood Plate 26, figure 10 



Teilina crystallina Wood, 181 5, General Conchology. 



