Dimensions. The great variation in the size of the species can be 

 noted by the following measurements: a specimen of large size from 

 the Upper Mercer member, length 12 mm., width 8 mm.; a large 

 specimen from the Anthony coal horizon, length 11 mm., width 6.7 

 mm., a small specimen from the same horizon, length 7 mm., width 

 4.5; an individual of average size from the Quakertown coal horizon, 

 length 6.5 mm., width 4.2 mm. 



Remarks. Lingula carbonaria is an important fossil of the Potts- 

 ville formation in Ohio as it is found on nearly every horizon, and on 

 some in the greatest profusion. In the bone shales associated with 

 the Anthony coal it is extremely abundant and forms the character- 

 istic fossil of that member. It also occurs in similar numbers in the 

 shales at various localities on other horizons, among which are the 

 Quakertown, Boggs, Upper Mercer, and Me Arthur. L. umbonata 

 Cox differs in having the greatest width about one-third the length 

 of the shell from the posterior margin, from which point the shell 

 contracts toward the front. L. kanawhensis Price is a much larger 

 and relatively broader form. 



Horizon and locality. Sharon ore horizon: Hamilton Tp., Jackson 

 County (locality 6), c. Anthony coal horizon: Scioto County (Local- 

 ity 7), aa. Quakertown coal horizon: Mogadore Station, Summit 

 County (Locality 12), aa. Lowellville member near Holbein, Mus- 

 kingum County (Locality 20), aa. Boggs member: Pine Creek, Scioto 

 County (Locality 24), a; Spook Hollow, Vinton County (Locality 25),a. 

 Present in middle and upper Pottsville formation. 



Lingula sp. 



Description. Large Lingulas of uncertain affinities are common 

 in the black bone shales of the Anthony coal horizon, at the mine 

 of the Buckeye Fire Brick & Clay Co., in Scioto County. Consider- 

 able variation exists in the form of the individuals, some being elongate 

 and narrow enough to resemble Lingula tighti Herrick, while others 

 are broader and suggest a possible identification with Lingula kanaw- 

 hensis Price. The lateral irargins are subparallel and the front, 

 especially on the broader forms, flattened; the surface is apparently 

 smooth. The material at hand, however, is too poor to permit satis- 

 factory conclusions to be reached. Two distinct species may be 

 present, or the differences in form may be due to compression, as the 

 specimens are all much flattened, so that the original shape was prob- 

 ably intermediate between the long slender form and the broader 

 one. The size is much greater than that of L. carbonaria Shumard, 

 and although common, it does not occur in the extreme profusion 

 of the latter species. It is of interest to note that the form under 

 discussion was found within one mile of the Wm. E. Dee mine where 

 L. carbonaria characterized the Anthony shales. 



Dimensions. An elongated, narrow form measures: length 

 16 mm., width 9.5 mm.; a broad variety: length 13 mm., width 8.5 m.m. 



45 



