BRACHIOPODA. 145 



Superfamily Spiriferacea 



Family Atrypidae 



Genus Atrypa Dalman 



Atrypa reticularis (Linnaeus) 

 Description and synonomy on pages 97 and 98 

 • Specimens are figured on plates 21 and 23 



Remarks — This species occurs in the Grand Tower, Beauvais, and St. Laurent but 

 is not abundant in any of the formations. 



Atrypa spinosa Hall 



Plate 34, figures 13 and 14 



Description and synonomy on page 98 



Figured on plate 20 



Remarks — Atrypa spinosa Hall is a common form in the Grand Tower limestone. 

 None of the specimens is as large as specimens from the Snyder Creek shale. The 

 average size is 20 mm. wide, 19 mm. long, 11 mm. thick. 



Family Spiriferidae 

 Genus Spirifer Sowerby 



Spirifer audaculus (Conrad) 

 Plate 33, figures 3, 4 and 5 



1842. Delthyris audacula Conrad, Jour. Acad. Nat. Sci., Philadelphia, VIII, p. 262 

 1857. Spirifer eatoni Hall, Tenth Rep. N. Y. State Cab. Nat. Hist., p. 157. 

 1867. Spirifera medialis Hall, Pal. New York, IV, pp. 227-229, pi. 38, figs. 1-25. 

 1882. Spirifera audacula Whitfield, Geol. Wisconsin, IV, p. 329, pi. 25, figs. 25, 26. 

 1894. Spirifer audaculus Hall and Clarke, Pal. New York, VIII, pt. 2, pp. 29-31, 



39, pi. 24, figs. 1-13; pi. 29, fig. 5. 

 1897. Spirifer audaculus Schuchert, Bull. U. S. Geol. Surv., 87, p. 382. 

 1901. Sptrifer audaculus Kindle, Indiana Dept. Geol. Nat. Res., 25th Ann. Rep., p. 



646, pi. 8, fig. 4. 

 1903. Spirifer audaculus Weller, Geol. Surv. New Jersey, vol. 3, p. 382, pi. 53, fig, 1. 

 1909. Spirifer audaculus Grabau and Shimer, North American Index Fossils, I, p. 



329, fig. 420 a. 

 1913. Spirifer audaculus Prosser and Kindle, Maryland Geol. Surv., Middle and 



Upper Devonian, pp. 192-193, pi. 18, figs. 7-9. 

 Description by Prosser and Kindle — "Shell medium size; valves moderately convex 

 in young specimens, becoming ventricose in old shells; hinge line generally extended 

 beyond the width of the shell below. Ventral valve usually more convex than the dorsal ; 

 incurved beak; cardinal area commonly of moie than medium height; longitudinally 

 striated and divided in the middle by the delthyrium which is about twice, as high as 

 wide; mesial sinus well defined, extending to the apex, of moderate width, rather deep 

 and generally rounded at the bottom. Dorsal valve moderately convex; beak small and 

 slightly incurved; cardinal area linear; mesial fold prominent, rising abruptly at the 

 sides and rounded slightly or flattened on top; cardinal angles slightly reflected. Sur- 



