PEGTEN (EUVOIA) sp. indet. 



The presence of a second species of the section Euvola is 

 indieatei hj fx-agnients of a small right valve. ^'hc shell is very 

 thin, feeblj- convex; exterior surface sc-aptured with about twenty- 

 five very weak, rounded radials, obsolete toward the umbo, separat- 

 ed by flattened interspaces about half as v/ide; concentrio increr.en- 

 tals fairly prominent; interior of the valve with v;eak radials of 

 about the sane order of magnitude as the external ones. 



Sxterzially this form is very ciose to P. gatimezisis Toula (l), 

 but comparison mth material in the Philadelvohia Academy collection 



(1). Jahrb. Z.-k. geol. -^eichsanstal t, vol. 58, up. 711-712, 



pi. 26, fig. 2, 190S (Hot P. (Amunjiym) ^atunensis "^oula, idem, 

 pp. 716-717, -ol. 26, fis. 10). 



from the Gatun beds shov;s that the Gatun species has external rad- 

 ials that are slightly higher toward the ventral marp:in and inter- 

 nally the interspaces between the radials are narrower ur.til near 

 the margin where they suddenly become -rider and deeper, the ribs 

 therefore becoming narrower and hip-her. It is possible, however, 

 that these differences are due t^ the difference in characters of 

 various growth periods, only fragments of larpe valves of p-atunen- 

 sis being available. 



"^he B-^wden form is separate^! from the associate'' bowdenensis 

 by its less conve : contour, the presence of flattened interspaces 



