18 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxx. 



yield hundreds of free examples while the limestone layers sometimes 

 show an abundance of specimens on their surfaces. The best develop- 

 ment of the species at Cincinnati occurs in the shales at a horizon 170 

 feet above low water mark in the Ohio Hiver. 



Occurrence. — South^ate member of the Eden shale, Cincinnati, Ohio, 

 and vicinit3^ 



BATOSTOMA VARIANS (James). 



Chaetetes rariuns James, Paleontologisit, No. 1, 1878, p. 2. 



Monticulipora {Chaetetes) r«r/ans James, Paleontologi.*t, No. 5, 1881, p. 36. 



Monticulipora varians Tames and James, Jour. Cincinnati Soc. Nat. Hist., X, 



1888, p. 177, pi. II, figs. 4((, Ji. — J. F. James, Jour. Cincinnati Soc. Nat. Hist., 



XVI, 1894, p. 199. 

 Batostomu varians Nickles and Bassler, Bull. U. S. Geological Survey, No. 173, 



1900, p. 179. 

 Batostuma variabile (part) Ulrich, Geol. Surv. Illinois, VIII, 1890, j). 460, pi. 



XXXV, figs. 4b^e (not 4, -ia, 5, or pi. xxxvi, fig. 1). 



The earliest description of this species was sufficient for its recog- 

 nition especially since it was compared with Chaetetes (now Batostoina) 

 jamesi Nicholson, of which good figures and a description had appeared 

 some vears before. James's description of 1881 also gives a fair idea 

 of the form and comparisons with the related B. jamesi. Ul rich's defi- 

 nftion and figures oi Batostorna variabile^'' prove upon further investiga- 

 tion to be founded upon at least two distinct species of Batostoma., one 

 of which as indicated above is synonymous with B. varians., while the 

 second is here recognized and redefined as B. variabile. The geological 

 occurrence of the two species is quite different, B. mrians ranging 

 from the Arnheim formation to and through the Whitewater forma- 

 tion of the Richmond group, and B. variabile being a characteristic 

 fossil of the uppermost beds of the same group. 



Comparing B. varians with B. jamesi^ the former is found to have 

 thin-walled, angular, instead of oval, thick-walled zocecia, few and 

 irregularly placed instead of numerous mesopores, fewer diaphragms, 

 and a lobate or subfrondesccnt zoarium instead of a regularly ramose 

 one as in the latter species. For good figures of both the internal and 

 exter.nal characters of B. varians., the student is referred to those 

 mentioned above under the citation of B. variabile. 



Occurrence. — Abundant in the Arnheim, Waynesville, Libert}^, and 

 Whitewater formations of the Richmond group in Ohio, Indiana, and 

 Kentuck3\ 



BATOSTOMA VARIABILE Ulrich (restricted). 

 Plate VII, figs. 9, 10. 



Batostoma variabile (part) Ulrich, Geol. Surv. Illinois, VIII, 1890, p. 460, pi. 

 XXXV, fig. 5; pi. XXXVI, fig. 1 (not pi. xxxv, figs. •ib^e=B. varians). 



As mentioned in the remarks under the preceding species, Ulrich's 

 Batostoma variabile includes at least two distinct forms, one of which 



a Geol. Surv. Illinois, VIII, 1890, p. 460. 



