BRA C HI POD A — TELOTREMA TA. 



335 



366. S. grimesi Hall. (Fig. 426.) Mississippi. 

 Very large and gibbous. Mesial fold and sinus broad and ill 



defined. Entire surface cov- 

 ered with very depressed .irre- 

 gularly bifurcating plications. 

 Kinderhook and Burling- 

 ton of Missouri, Illinois, Iowa, 

 Arctic North America lat. 

 82°43 / . 



367. S. neglectus Hall. 



Mississippic. 



Hinge line less than width 

 of shell below and rounded 

 at the extremities. Pedicle 

 valve a little more convex 

 than the brachial with 

 strongly arched beak and 

 cardinal area. Mesial fold 

 and sinus small at beak but 

 increasing very rapidly in 

 width toward the front. Sur- 

 face marked by about 6 plica- 

 tions on each side the fold 

 and sinus. 



Keokuk of Illinois, Iowa, 

 Nevada. 



Fig. 426. 



ter Hall. ) 



Spirifer grimesi, X %• (Af- 



368. S. logani Hall. (Fig. 427.) Mississippic. 

 Very large, gibbous. Length and width as three to four. Fold 



in brachial valve very prominent and elevated. Sinus in pedicle 

 valve broad and undefined, produced anteriorly. Surface, includ- 

 ing fold and sinus, covered with small, nearly equal plications. 

 Keokuk o( Illinois, Tennessee and Missouri. 



369. S. leidyi Norwood and Pratten. (Fig. 428.) Mississippic. 

 Small. Pedicle valve gibbous ; brachial valve depressed-convex. 



Mesial fold bearing a well defined depression in the center, reach- 

 ing half way to the beak. Surface marked by 7 or 8 plications 

 and by longitudinal and concentric stride. 



St. Louis of Kentucky, Indiana, Illinois, Utah, Nevada. 



