44 PROCEEDINGS OF THE NATION AI. MUSEUM. vol. xxx. 



Although Mr. James gave a fair definition of this .species in the 

 Catalogue,*^ our knowledge of the form reall}' dates from Nicholson's 

 work in 1881. 



The species is a rather al)undant and characteristic fossil of the Cor- 

 rj^ville mem})er, and ma}' be distinguished from other forms of the 

 genus by its looselj^ incrusting habit of growth, strong and closely set 

 monticules, and numerous mesopores. Its internal characters are 

 those of a typical Monticuliponi , cystiphragms occurring in both the 

 immature and mature regions, while the walls have the peculiar 

 granulose structure characterizing that genus. 



Ocean'ence. — Corrj^ville member, McMillan formation, Cincinnati, 

 Ohio, and vicinity. 



MONTICULIPORA CLEAVELANDI James. 



Monticulipora{IIeterotrypa f) deavelandi James, Paleontologist, No. 6, 1882, p. 49, 



pi. I, fig. 7. 

 Montiail.ij)ora cleavelandi J AUEs and J AMES, Jour. Cincinnati Soc. Nat. Hist., XI, 



1888, p. 15, pi. I, fig. 4. — J. F. James, Jour. Cincinnati Soc. Nat. Hist., XVIH, 



1895, p. 68. 

 Mo7iticuliporu dearelamU Ulrich and Bassler, Smithsonian Misc. Coll. (Quart. 



issue), XLVII, 1904, p. 16, pi. vi, figs. 4-6. 



This is one of the most easily recognized bryozoa of the Cincinnati 

 rocks, inasnuu'h as it is the only ramose species of Monticuli-povd so 

 far known from these strata. A vertical fracture when examined 

 under the hand lens will show the presence of C3'stiphragms in l)oth 

 the axial and peripheral regions, thus indicating its generic position 

 luider MoiitlcnlljH'i'a. The specific characters are particularly the 

 ramose habit of growth and the absence of mesopores. 



Ulrich and the writer ^ have recently redefined this species and given 

 figures of the internal structure. None of the James desci'iptions are 

 adequate for the recognition of the species, inasmucb as tlie method 

 of growth and internal characters attributed to it by them do not 

 agree with the specimen marked as the type. This reason would 

 doubtless have justified the rejection of the name, l)ut as the species 

 had not been described in the meantime it was deemed advisable to' 

 establish it imder the same name proposed for it by James. 



Oecurreuce. — Veiy al)undant at several localities in Clinton County, 

 Ohio, where the WhitewatiM- formation of the Richmond group is 

 exposed, riames's type is from a locality near L3'nchburg, Highland 

 County, Ohio. 



«Catal. Sil. Foss., Cincinnati group, 1875, p. 2. 

 * Smithsonian Misc. Coll., XLVII, 1904, p. 16. 



