26o Bulletin 39 432 



Genus PSAMMOSOLEN, Risso 



Psammosolen gatunensis Toula, var. costaricensis, n. var. 



Plate 29, figure 7 

 Solecurtus gatunensis Toula, 190S, Jahrb. der K-K. Geol. Reichsan- 



stalt, vol. 58, p. 732, pi. 28, fig. 12. 

 Solecurtus gatunensis Brown and Pilsbry, 191 1, Proc. Acad. Nat. Sci. 



Phila., vol. 58, p. 372. 



Shell rather large, elongate, convex, the dorsal and ventral 

 margins straight and parallel; the low, inconspicuous beaks sit- 

 uated at the anterior y>>, the anterior end rounded, the posterior 

 subtruncate; two low, radial depressed rays extend from the 

 beaks obliquely to the ventral margin; the central part of the 

 shell and the anterior end is sculptured roughly with irregular 

 growth lines; the posterior dorsal slope has strong, vertical or 

 slightly oblique lines which cross the finer concentric growth 

 lines; in addition the whole surface of the shell is roughened by 

 small, short threads as if the surface had been painted with a 

 stiff brush. 



I^ength 63, height 25.50, diameter of the right valve 

 14.50 mm. 



Toula' s figure of an internal mold shows a smaller shell, a 

 strong anterior-umbonal angle and a somewhat shorter anterior 

 end. It is possible that the two forms are distinct but we lack 

 a good comparative series of the Gatun shell. A smaller and 

 more delicate species of Psammosolen occurs at several localities 

 in the Costa Rican Gatun. It is not the P. strigillatus (Z.) of 

 Toula, differing in its pointed anterior end. 



Gatun Stage: Rio Betey. 



Genus SANGUINOLARIA, Lamarck 

 Section SAMMOTELLA, Blainville 

 Sanguinolaria afouatta, n. sp. Plate 29, figures 5, 6 



Shell rather large, elongate; and rostrated behind; left 



