OF DENISON UNIVERSITY. 
73 
Rh. lepidodendroidea, Meek. From this it may be distinguished by 
the following characteristics. The mature region of the cells appears 
more abruptly inclined to the immature region of the cells ; the ridges 
between the cells are covered with smaller and more numerous gran- 
ules, these are also present on the slopes of the vestibules, and are not 
arranged in such well defined rows as in the other species. Meek in 
his description of the type specimens gives the following measure- 
ments: number of cells in .2 inch, measuring longitudinally, 12; 
number of cells in .oc; inch measuring in the direction of the oblique 
rows, 4. We have specimens from Kansas City which agree very 
well with these measurements. The Ohio specimens on the other hand 
present the following measurements: ^ number of cells in .3 inch, 
measuring longitudinally, 17 ; number of cells in .05 inch, measuring 
in the direction of the oblique rows, 6. 
Rare at Flint Ridge. {Multipora many pores or cells.) 
II. Rhombopora lepidodendroidea. Meek. 
{Plate VII, Fig. 3. a, b.) 
Zoarium branching, branches about i mm. wide, or slightly less. 
Cells arranged in diagonal intersecting and in longitudinal series. 
Longitudinally, 6 ceils occupy a length of 2 mm ; about 13 longitudi- 
nal series surround the stem. Vestibule elongated, smooth, sharply 
distinguished from the intermediate granule- bearing ridges. Granules 
strong, readily seen even under a low magnifying power, arranged in 
one, two, or even three rows along the ridges. At one end of the 
vestibule a low node is frequently seen. The thin, immature portion 
of the cells curves gradually outward into the mature portion, where 
the curvature is increased and the walls become decidedly thickened. 
The stems branch at intervals varying from 15 to 25 mm. 
From the western forms of this species which we have seen, the 
Ohio specimens show several variations. The branches are much nar- 
rower, and instead of 4 cells, 5 cells may be counted in a distance of 
.05 inch. The vestibules also appear more elongated. However the 
fact that the branches are narrower would perhaps be sufficient to ac- 
count for the other variations. Its wide geographical distribution is 
also of interest in this connection. Meek mentions the species from 
Nebraska,_ Kansas, Iowa, Missouri, and Illinois. In species of wide 
