70 BRACHIOPODS. 



Plectambonites rhomboidalis (WILCKBNS). 



Plate xxxix, fig. 6. 

 Conchita rhomboidalis Wilckens, 1769 : Nachreicht. von seltenen Verst., p. 



77, pi. viii, figs. 43-44. 



Strophomena rhomboidalis Lindstrom, 1860: Goth. Brach., p. 371. 

 Strophomena rhomboidalis Meek, 1873 : Geol. Sur. Ohio, vol. I, Pal. , p. 75, 



pi. v, figs. 6d-e. 



Like Strophomena but with flattened, visceral area covered 

 with prominent concentric wrinkles, and with abruptly up- 

 turned frontal and lateral borders. 



Horizon and localities. Lower Silurian, Hudson shales : 

 Cape Girardeau ; Lower Carboniferous, Chouteau ( Kinderhook) 

 limestone: Curryville (Pike county); Burlington limestone: 

 Louisiana. 



Strophodonta demissa (CONRAD). 



Plate xxxix, figs. 7a-b. 



Strophodonta demissa Conrad, 1842: Jour. Acad. Nat. Sci., Phila., vol. 



VIII, p. 258, pi. xiv, fig. 14. 



Strophodonta demissa Hall, 1857: Reg. Rep. State Cab. Nat. Hist., p. 137. 

 Strophodonta demissa Hall, 1858: Geology Iowa, vol. I, p. 495, pi. ill, 



figs. 5a-k. 

 Strophodonta navalis Swalldw, 1860: Trans. St. Louis Acad. Sci., vol. I, 



p. 365. 

 Strophodonta callawayensis Swallow, 1860: Trans. St. Louis Acad. Sci., 



vol. I, p. 638. 

 Strophodonta quadrata Swallow, 1860 : Trans. St. Louis Acad. Sci. , vol. I, 



p. 639. 

 Strophodonta oequicoslata Swallow, 1860: Trans. St. Louis Acad. Sci., vol. 



I, p. 639. 



Shell semi-elliptic, about as wide as long ; hinge-line usu- 

 ally slightly longer than the greatest width ; cardinal area nar- 

 row. Surface marked by strong, angular costae. 



Horizon and localities. Devonian, Callaway limestone: 

 Dauphin ( Callaway county ). 



Strophomena alternata (CONRAD). 



Plate xxxix, fig. 3 



Leptcena alternata Conrad, 1838: Ann. Rep. Geol. New York, p. 115. 

 Strophomena alternata Conrad, 1839: Ann. Rep. Geol. New York, p. 62. 

 Leptcena alternata Hall, 1847: Pal. New York, vol. I, p. 202, pi. xxxi, 



figs. 10-20. 

 Strophomena alternata Meek, 1873: Geol. Sur. Ohio, Pal., vol. I, p. 88, 



pi. vii, figs. la-g. 



