BRADLEY: BRACHIOPODA OF THE UAQUOKETJ! OF IOWA. 509 



tlu i shell; cardinal angles tend to squareness so as to produce an 

 approximately rectangular outline. 



The pedicle-valve has a medial ridge, gently convex a1 the .'interior 

 edge, I »u t growing sharper tow aid the posterior margin where it 

 merges into ;< pointed beak, thai de\ iates but slightly from t be \ ertical. 



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

 possesses ;i shallow sinus which begins ;it the anterior margin and 

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

 ity of the shell. 



Striatums are weD 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: — 



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

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



Hebertella (Glyptorthis) insculpta (Hall). 



Orthis insculpta Hall, 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, 1855, 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. X. 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. 

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



(gen. ref.). 

 Orthis bellarugosa Hall (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; 

 \Yisconsin; Iowa; Minnesota; Tennessee. 



