250 Cincinnati Society of Natural History. 
amples before me, there is a regular gradation from this specimen 
down to what is nothing more than a pronounced node, and after a 
careful examination of these specimens, I find that this habit of growth 
is, apparently, alwavs due to a lack of surface over which the zoarium 
might spread in its normal fashion. The direction of growth in the 
examples in question is, in every instance, toward the end of the branch 
of the ramose bryozoan incrusted. As growth proceeded, the foreign 
branch was gradually left behind, and in consequence, the tubes in the 
central portion of the zoarium are forced to remain in an “immature” 
condition for a much longer time than is the case in the normal 
parasitic condition. It is true, that with only a few exceptions, all the 
ramose and frondesvent bryozoa are attached to some foreign body by 
a more or less expanded base ; and I am fully pursuaded that, what I 
must now regard as aberrant forms of Atactoporella, are clearly pre- 
dictive of truly ramose or frondescent species of like character. 
This species differs from all the other species of the genus now 
known, in its greater regularity of cell structure, and more numerous 
interstitial tubes. 
Formation and locality: Cincinnati Group. Rather rare in the 
lower 100 feet of strata exposed at Cincinnati, Ohio, and Covington, 
Ky. 
ATACTOPORELLA NEWPORTENSIS, n. sp. (Pi. XIL, figs. 4-40). 
Zoarium robust, growing upon foreign objects, lobate, or throwing 
off subramose shoots. At intervals of about .12 of an inch, measuring 
from center to center, the surface is elevated into more or less 
prominent, rounded, and often elongated monticules, the summits and 
slopes of which are occupied by cells a little larger than the average. 
Cells rather regularly arranged in intersecting series, from eleven to 
thirteen of the ordinary. size in the space of .1 inch, with subcircular 
or ovate apertures, having an average diameter of ;4,th of aninch. On 
finely preserved examples the apertures are surrounded by a slightly 
elevated rim or peristome, which is often a little inflected at the points 
occupied by the numerous, though very small, spiniform tubuli. In- 
terstitial cells numerous, but as usual with species of this genus, they 
are not readily detected externally. 
Internally this species is in many respects precisely like A. typi- 
calis. In tangential sections (PI. XIL, fig. 4a) the cells are seen to be 
somewhat unequal, narrower, the walls less inflected, and the spiniform 
tubuli smaller than in that species. Externally they differ in their 
