BRADLEY: BRACHIOPODA OF THE MAQUOKETA OF IOWA. 509 



the shell; cardinal angles tend to squareness so as to produce an 

 approximately rectangular outline. 



The pedicle-valve has a medial ridge, gently convex at the anterior 

 edge, but growing sharper toward the posterior margin where it 

 merges into a pointed beak, that deviates but slightly from the vertical. 



The brachial-valve is about equally convex with the pedicle and 

 possesses a shallow sinus which begins at the anterior margin and 

 continues nearly to the beak, where it merges into the general convex- 

 ity of the shell. 



Striations are well defined, almost coarse; thirty-eight to forty- 

 four occur along the anterior margin. The lateral striae increase by 

 bifurcation; the medial ones are always simple. 



A typical specimen measured: — 



Striations of 

 Length Width Convexity pedicle-valve 



13 mm. 15 mm. 6 mm. 40 



Locality: — Lower Maquoketa in the vicinity of Clermont, Iowa. 

 Holotype, M. C. Z. 8,537. 



Hebertella (Glyptorthis) insculpta (Hall). 



Orthis insculpta HaU, Pal. N. Y., 1847, 1, p. 125, pi. 32, fig. 12. Billings, Geol. 



Canada, 1863, p. 167, fig. 150. Meek, Pal. Ohio, 1873, 1, p. 99, pi. 9, 



fig. 1. Miller, Cine, quart, journ. sci., 1875, 2, p. 40. Emmons, Amer. 



geology, 18.55, 1, pt. 2, p. 195, pi. 9, fig. 12. Shaler, Mem. Geol. surv. 



Kentucky, 1876, 1, p. 30. 

 Orthis {Hebertella) insculpta Winchell and Schuchert, Geol. Minn., 1893, 3, 



pt. 1, p. 435. 

 Hebertella insculpta Hall and Clarke, Pal. N. Y., 1892, 8, pt. 1, p. 222, pi. 5A, 



fig. 13. Cumings, 32nd Ann. rept. Dept. geol. nat. res. Indiana, 1908, 



p. 905, pi. 34, fig. 2-2d. 

 Ghjptorthis insculpta Foerste, Bull. Sci. lab. Denison univ., 1914, 17, p. 258 



(gen. ref.). 

 Orthis bellarugosa HaU (not Conrad), 2d. Ann. rept. N. Y. state geol., 1883, 



pi. 35, fig. 22. 



Three specimens from Clermont had the following dimensions: — 



Length Width Greatest convexity 



15 mm. 18 mm. 7 mm. 



9 mm. 11 mm. 5 mm. 



10 mm. 13 mm. 6 mm. 



Locality: — Oxford, etc., Ohio; Indiana; Wilmington, Illinois; 

 Wisconsin; Iowa; Minnesota; Tennessee. 



