American Paleozoic Bryozoa. 167 
Hamilton and Cincinnati, O., at an elevation of about 375 feet above 
low water mark in the Ohio river. 
SPATIOPORA MACULOSA, n. sp. (PI. VIL, fig. 6.) 
Zoarium forming large and very thin parasitic expansions, usually 
adhering to the shells-of Orthoceras, but in a few instances to other 
objects. The surface shows at intervals of .18 inches, measuring from 
center to center, distinct groups of large cells, which, very rarely, how- 
ever, are slightly elevated above the general level of the surface. ‘The 
diameter of the cells in these clusters not infrequently exceeds ~.th of 
an inch, while that of the ordinary cells averages about ;+;th of an 
inch. Tle cell-walls are moderately thin, and at many of the angles 
are elevated into more or less prominent spiniform tubuli, which are 
larger and somewhat more numerous among the cells of the clusters 
mentioned. The cell-apertures are more or less irregular in shape, and 
never, on account of the thickened wall angles, are strictly angular. 
Interstitial cells are entirely absent. The internal structure shows no 
striking peculiarities, and much resembles that of the type species. 
This species is not uncommon in the Cincinnati Group. It is dis- 
tinguished from S. aspera by the more distinct groups of larger cells, 
smaller and less prominent spiniform tubuli, which are only to be ob- 
served in finely preserved examples, the greater number of specimens 
found being entirely smooth. 
Formation and locality: To be found at most localities in the Cin- 
cinnati group, but it can not be said to be common at any. 
SPATIOPORA LINEATA, n. sp. (Pl. VIL., fig. 7.) 
Zoarium consisting of excessively thin expansions, adhering to the 
shells of Orthoceras. Cells rounded, or oblong, arranged in regular 
longitudinal series, and in somewhat less regular transverse or inter- 
secting rows. There are no monticules nor distinct groups of larger 
cells ; the cell-walls between the slightly elevated intersections are 
quite thin ; measuring along one of the longitudinal series nine or ten 
cells may be counted in the space of .l inch. On account of the ex- 
treme tenuity of the zoarium, the sections prepared of this species are 
unsatisfactory. 
This species is readily separated from the other non-tuberculated 
species of the genus by the regular arrangement of its cells in longitu- 
dinal series. From S, tuberculata, Edwards & Haime, sp., which 
sometimes assumes a similar cell arrangement, it is distinguished by 
its smooth surface, the zoarium of that species being elevated at inter- 
vals into rather large monticules. 
