WAVERLY GROUP SPECIES. 275 



place it as a variety of F. multiporata until its relations to that form can 

 be determined by a comparison of authentic specimens. 



Locality and position : Lodi, Ohio. Shaly beds of the Waverly group. 



BRACHIOPODA. 



Genus LINGULA, Bru.^uiere, 1792. 



(Encyc. Math. Tab., 250.) 



LiNGULA (LlNGULELLA ?) MEMBRANACEA, Wincliell. 



Plate 14, fig. 4. 

 Lingula membranacea, Winch ell (1863); Proceed. Acad. Nat. Sci., Philad., XV., 3. 



Shell attaining about a medium size, compressed, longitudinally ob- 

 long, with length nearly twice the breadth, and lateral margins almost 

 straight and parallel, or but very slightly convex in outline; anterior 

 margin rounded or sometimes faintly subtruncatecl; beak very obtuse, 

 with a narrow faint ridge extending from it a short distance forward. 

 Surface appearing smooth, but on close examination showing very ob-_ 

 scure traces of fine concentric striae. 



Length, 0.78 inch ; breadth midway between the front and middle, 0.45 

 inch; do. at same distance from anterior end, 0.42 inch. 



The specimen from which our figure and description were prepared 

 seems to be mainly an internal cast of the dorsal valve, judging from the 

 obtuseness of the beak. The little ridge extending forward from the 

 beak has somewhat the appearance of being the cast of a small furrow of 

 the cardinal margin, for the passage of the peduncle. If this appearance 

 is not deceptive, the species would doubtless fall into Mr. Salter's group 

 Lingidella. In our figure this little ridge is represented slightly too 

 thick, and scarcely long enough, while the lateral margins of the figure 

 are also a little too straight, and its anterior region scarcely wide enough, 

 proportionally. 



This seems to be a marked form, readily distinguished by its longitud- 

 inally oblong form, nearly straight and parallel sides, and compressed 

 valves. 



I have not had an opportunity to compare our specimens with Prof. 

 Winchell's types, but our shell agrees so nearly with his description that 

 I am inclined to believe it belongs to his species. 



Locality and position : Prof. Winchell's type specimens came from the yellow, fine, 

 arenaceous beds under the Burlington limestone, at Burlington, Iowa, belonging to 

 the horizon of the Waverly group of Ohio, while that we have figured was found at 

 about the same horizon, at Hart's Grove, Ashtabula county, Ohio. 



