298 
Aug. F. Foerste 
Dr. George M. Austin collected a typical specimen in the 
Waynesville member at Clarksville, Ohio (illustrated in this bul- 
letin). Many of the monticules are abruptly conical, and fully 
one millimeter high. They are arranged more or less in series 
along the crests of the radiating plications of a Byssonychia, about 
4 or 5 monticules occurring in a length of 10 millimeters. The 
papillae also are arranged in series parallel to the plications, about 
6 or 7 in a length of 2 millimeters. The incrustations of Dermatos- 
troma scahrum usually are thicker than those of Dermatostroma 
papillatum. This raises the question whether Dermatostroma 
scahrum may not be merely the more mature form of Dermatostroma 
papillatum. 
When attached to smooth surfaces, the monticules do not show 
any tendency toward arrangement in rows. There is no doubt, 
however, about the influence of the plications or narrow ridges of 
the supporting shells upon the arrangement of these monticules. 
11. Dermatostroma glyptum, Foerste 
(Plate I, Fig. 2 ) 
1910. Ldbechia corrugata glypta Foerste, Bull. Sci. Lab. Denison Univ., 16, p. 
p. 87. (July 15) 
1910. Dermatostroma corrugatum Parks, Univ. Toronto Studies, Geol. Series, 7, 
p. 33, Plate 2U, Fig. 7. (October) 
The type specimen, here figured, belongs to Dr. George M. 
Austin, and was found by him on Dutch creek, northwest of Wil- 
mington, Ohio, in the upper part of the Whitewater member of the 
Richmond. 
Papillae coarse, varying greatly in number in different parts of 
the same specimen ; usually from 3 to 4 in a length of 2 millimeters, 
but locally increasing to 6 in the same distance. In addition to 
papillae there are ridge-like elevations, varying greatly in length. 
The shorter of these ridges consist of a uniserial line of papillae, or of 
a more or less irregular agglomeration of papillae, of larger height and 
width than the remainder, so united as to form short ridges or ir- 
regular elevations, and between the latter occur the ordinary papil- 
lae. In addition to the shorter ridges, there are also longer ridges 
extending in a very irregular, vermiform manner across the surface, 
the ridges often crossing each other. These longer ridges occasion- 
ally have the appearance of being the limiting edges of separate 
individuals of the same species which have become attached to the 
