BRACHIOPODA—ATREMATA. 



197 



25. L. cuneata Conrad. (Fig. 230.) 



Wedge-shaped, very acute at beaks, 

 converging uniformly from beak to front 

 curved (almost truncate). Valves con- 

 vex on the posterior half but flattened 

 anteriorly. Surface longitudinally stri- 

 ated. 



Medina of New York. 



Siluric. 



Margins nearly straight, 



which is but slightly 



Fig. 230. Lingula cuneata 

 enlarged, X 2. (After Hall & 

 Clarke. ) 



26. L. clintoni Vanuxem. Siluric. 



Sides of shell straight and nearly par- 

 allel; abruptly rounded at beak, abruptly 

 truncate at front. Shell flat anteriorly 

 but elevated into a ridge at beak and 

 hence here very convex. Surface 

 marked by concentric growth lines and radiating striae.^ 



Clinton of New York, Pennsylvania, Ontario, Nova Scotia. 



27. L. ligea Hall (Fig. 229, d.) Devonic. 

 Narrow elliptical with length twice the 

 width. Sides slightly curving. Extremities 

 subequal, with obtuse beak and broadly 

 rounded front. Surface marked by fine con- 

 centric striae. 

 Hamilton-Portage of New York, Ohio, Nevada, Ontario. 



28. L. spatulata Vanuxem. (Fig. 231.) Devonic. 



Minute, spatulate, moderately convex; attenuate toward the 

 beak ; widest across the middle. Length (scarcely three tenths of 

 an inch) about twice the width. Surface 

 marked by fine concentric striae. 



Genesee and Portage of New York, Ohio, 

 Canada and elsewhere. 



Fig. 231. Lingula 

 spatulata, X 2 - 



29. L. Cuyahoga Hall. (Fig. 232, a.) a 



Devonic-Lower Carbonic, fig. 232. 

 Length and breadth about as five to cuyahoga, x 

 three. Sides nearly parallel, converging 6 * Singula melie large speci- 



& men, X 2 ; (Meek.— Ohio 



b 



a, Lingula 

 (after Hall) 



slightly toward the cardinal margins. Beak 

 obtuse; front subtruncate. Surface covered 

 by fine concentric striae. 



Chemung- Waverly of New York, Ohio. 



Pal.) 



