394 Proceedings of the Ohio State Academy of Science. 



by faint concentric undulations of unequal strength, but most 

 strongly marked on the posterior end and on the umbonal slope 

 [Whitfield, 1895]." 



Length 22 mm. ; height 1 1 mm. 



The shell is readily distinguished from the other species of 

 AUorisma by its smaller size and more transversely cylindrical 

 outline. 



Fig. 19. — AUorisma iiia.rz'illensis. 



a. — A view of the right valve of a specimen. 



b. — A view of both valves of an individual. (After Whitfield.) 



Horizon and locality. — Maxville limestone. 



Upper zone : Below Thompson Residence, White Cottage. 



Shale-nodular zone : Cut No. 5, Upper end Cut No. 6, Alt. 

 Perry-Fultonham ; Stimmel Residence, jMaxville. 



Lower zone : Cut No. 4, Alt. Perry-Fultonham. 



Undetermined zone : Aliddle of Cut No. 6, Mt. Perry-Fulton- 

 ham; Harper Shaft (?), Olive Furnace. 



CYPRICARDELLA OBLONGA— Hall. 



1856. Cypricardella obloiiga. Hall, Trans. Albany Inst., Vol. IV, p. 18. 

 St. Louis limestone : Spergen Hill and Bloomington, Indiana. 



1882. Microdon {Cypricardella) ohlonga. Whitfield, Bull. Am. Mus. 



Nat. Hist., Vol. I, p. 65, pi. 7, figs. 30-34. 

 St. Louis group : Spergen Hill and Bloomington, Indiana. 



1883. Cypricardella oblonga. Hall, Ind. Geol. and Nat. Hist., l'2th Rep., 



p. 340, pi. 30, figs. 30-34. 

 St. Louis group : Spergen Hill, Lanesville, and Bloomington, In- 

 diana. 

 1906. Microdon ohlonga. Beede, Ind. Dept. Geol. Nat. Res., 30th Rep., 

 p. 1330, pi. 23, figs. 30-36. 

 Salem limestone : Spergen Hill and Bloomington, Indiana.. 



