150 Cincinnati Society of Natural History. 
but the material now at hand proves this view untenable. Dr. Nichol- 
son’s specimens doubtlessly represent the terminal branches of a 
typical example of Edwards and Haimes’ species, the branches of that 
portion of the zoarium always being more strictly dendroid, and of 
smaller size than the primary ones. 
Dekayia trentonensis, n. sp., is interesting, not only from the fact 
that it is the earliest species of the genus so far known, but also be- 
cause its cell-walls are thicker than is usual, and closely resemble those 
of a Heterotrypa. On the other hand, its growth, few if any intersti- 
tial tubes, and the large size of the spiniform tubuli, in which respect 
the species almost rivals D. aspera, are characters pointing with much 
certainty to Dekayta. 
Another interesting form is found in D. paupera, n. sp. In this 
species the cell-walls are excessively thin, and the spiniform tubuli are 
creatly reduced in size (7. e. compared with those of D. aspera). But 
its general appearance, the absence of interstitial cells, the distribution 
of the spiniform tubuli, and, more than all, its close relationship to D. 
appressa, confirm me in my opinion that it is properly referred to the 
genus. 
DEKAYIA PELLIOULATA, 0. Sp. (Plate VI., figs. 9 and 9a. ) 
Zoarium ramose, with smooth, thick, mostly rounded, sometimes 
slightly flattened branches, arising from a‘“large basal expansion, 
and gradually tapering from the base, where their diameter varies 
from .5 to 1.0 inch, to their terminal ends, where the diameter is 
usually not over .3 inch. On well-preserved examples the cell aper- 
tures over large patches of the surface are covered by a thin pellicle, 
the cell walls appearing as only very faintly elevated lines upon 
its surface, while the surface extensions of the spiniform tubuli are 
more distinct and prominent. than when the pellicle is wanting. 
About five may be counted in .l inch. At distances.apart of about 
.1 inch, the surface shows clusters of cells slightly larger than those of 
the average size, interspersed among which are small and unequal ag_ 
oregations of much smaller cells, that in all probability represent the 
apertures of interstitial tubes. Cells with moderately thin walls, 
angular, those of the ordinary size varying in diameter from 54th to 
jipth of an inch, while that of those forming the clusters mentioned 
rarely exceeds },th of an inch. 
In longitudinal sections the tubes in the axial region have, as usual, 
excessively thin walls, and are only occasionally provided with an iso- 
