26o 



Bulletin 39 



43« 



Genus PSAMMOSOLEN, Risso 



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



Plate 29, figure 7 



Solecurtus gatunensis Toula, 1908, Jahrb. der K-K. Geol. Reichsan- 



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

 Solecurtus gatune7i sis 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 ^, 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. 



Length 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 {L) of 

 Toula, differing in its pointed anterior end. 



Gatun Stage: Rio Betey. 



Genus SAfMGUINOLARIA, Lamarck 

 Section SAMMOTELLA, Blainville 



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



Shell rather large, elongate; and rostrated behind; left 



