144 Systematic Paleontology — Middle Devonian 



fifth or sixth hcins' stronger than the intermediate ones. In this species 

 the striae are all of about equal strength. 



Occurrence. — Eomxey Formation, Onondaga Member. Tonoloway; 

 1% miles south of Berkeley Springs. 



Collection. — U. S. N"ational Museum. 



[E. M. Kindle.] 



Genus SCHUCHERTELLA Girty' 

 SCHUCHERTELLA VARIABILIS n. Sp. 



Plate XI, Figs. 6-10 

 Schuchertella cf. perversa Kindle, 1912, BuH. U. S. GeoL Surv., No. 508, p. 76. 



Description.- — Shell semielliptieal and symmetrical or with slight um- 

 bonal distortion ; hinge-line straight and somewhat less than the greatest 

 width of the shell; lateral margins curving toward the hinge-line and 

 the front of the shell. Ventral ( ?) valve slightly convex from the umbo 

 toward the center and flattened towards the front and sides of the valve. 

 Surface marked by 50 rather sharp and close radiating striae on the 

 smaller specimens and in the middle of many of the interspaces is a 

 short and much smaller intercalated one; while the larger specimen has 

 about 60 of the strongest striae which extend quite or nearly to the umbo 

 and most of the interspaces show an intercalated one in the center, 

 second in strength to the primary, with a still fainter one on each side, 

 making three grades of striae; a few of the interspaces show only one. 

 The surface also crossed by very fine, thread-like and closely arranged 

 concentric striae which are the most conspicuous on the interspaces. 



* Dr. Girty, in 1904, proposed the generic name Schuchertella " for shells hav- 

 ing the type of structure for which the name Orthothetes is at present in general 

 use," for which he stated " there is no authority for spelling otherwise than 

 Orthotetes." Dr. Girty shows that Fischer de Waldheim applied the name 

 Orthotetes to a different type of structure than that for which it has been used 

 in recent years and therefore he has transferred it to the group of shells for 

 which it was originally used, which later had been named Derhya by Waagen, 

 and proposed the new name for the group left without a generic name (Proc. 

 U. S. Nat. Mus., vol. xxvii, 1904, p. 734). 



