372 C. L. Fenton— The Eacklerry Stage of 



Productella speeiosa Hall. 

 Gypidula comis munda (Calvin). 7 

 Gypidula comis (Owen) n. var. 

 Rhynchonella subacuminata Webster. 

 Camarotoechia contract a saxatilis Hall. 

 Rhipidomella cf. penelope Hall. 

 Pugnoides altus (Calvin). 

 Pugnoides ambiguus Calvin. 

 Liorlrynclms iris Hall. 

 Liorhynchus sp. undet. 

 Centronella navicella (Hall). 

 Cranaena calvini (H. & W.). 

 Atrypa reticularis (Linnaeus). 

 Atrypa reticularis hackberryensis (Webster). 8 

 Atrypa reticularis alta Fenton. 

 Atrypa reticularis n. var. 

 Atrypa hystrix (Schlothein). 

 Atrypa hystrix planosulcata Webster. 

 Atrypa spinosa Hall ? 

 Atrypa aspera Hall. 

 Atrypa aspera elongata Webster. 

 Spirifer whitneyi Hall. 

 Spirifer whitneyi productus Fenton. 

 Spirifer whitneyi gradatus Fenton. 

 Spirifer whitneyi rockfordensis Fenton. 

 Spirifer, cf. fornacula Hall. 

 Spirifer orestes H. & W. 

 Spirifer orestes websteri Fenton. 

 Spirifer cyrtinaformis H. & W. 

 Spirifer cyrtinaformis helense Fenton. 

 Spirifer macbridei Calvin. 

 Spirifer ( ? ) hungerf ordi Hall. 

 Spirifer ( ? ) septentrionalis Webster. 9 

 Cyrtina hamiltonensis recta Hall. 

 Reticularia n. sp. (called R. fimbriata (Con.)). 

 Athyris, cf . minutissima Webster. 

 Pelecypoda 



Gramysia sp. undet. 

 Sphenotus contractus Hall ( ? ) 

 Leptodesma sp. undet. 

 Lucina (?) sp. 

 Paracyclas sabini White. 



7 Described by Calvin as Gypidula munda; later (la. Geol. Surv. VII) 

 referred to by nim as not widely different from G. comis, and here placed 

 as a variety of that species. 



8 Described as Atrypa Tiackoerryensis, but not specifically distinct from 

 A. reticularis as at present understood. 



9 Originally described as Spirifer northerna Webster. The name is here 

 changed by the author of the species, C. L. Webster. 



