NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
777 
Affinities. — This species is easily confused with Idmidronea maxillaris Lons- 
dale, 1845, in which the dorsal presents the same great development. It differs 
from it in the complete absence of firmatopores which are visible either by abra- 
sion, or in longitudinal sections. 
It differs from Idmonea tumida Smitt, 1866, in the much less separation of 
the fascicles (0.20 and not 0.50 mm.). 
Occurrence^ — Middle Jacksonian (Castle ITayne limestone) : Wilmington, 
North Carolina (very common). 
Upper Jacksonian (Ocala limestone) : Alachua, Florida (rare) ; west bank 
Sepulga River, Escambia County, Alabama (rare). 
Cotypes. — Cat. No. 65352, U.S.N.M. 
IDMONEA GRALLATOR, new species. 
Plate 138, figs. 1-20. 
Description. — The zoarium is small, filiform, linear, bifurcated, horizontal, 
with oval transverse section which is a little higher than wide. The fascicles are 
salient, little oblique, arranged alternately on each side of the median axis and 
quite distant from it. They are formed by four or five zooecia, the last of which 
is quite small. The tubes are visible, flat, separated by a salient thread. The 
basal lamella is convex, flat, or somewhat concave; it is striated longitudinally 
by the tubes and transversally by the convex zones of growth; it bears radicells 
of consolidation. The ovicell is quite elongated between six or seven fascicles. 
•Diameter of tire tubes 0.12 mm. 
Distance between the fascicles 0.34—0.40 mm. 
Measurements.— Width of the f asc i c i es 0.14 mm. 
Width of the zoarium 0.8 mm. 
Variations. — The fascicles are quite salient and quite divergent from the 
median crest (figs. 2, 3) ; abrasion lessens this character (fig. 6). The dorsal is 
quite variable; it is flat on the young branches (fig. 8) ; but the older branches 
are convex (fig. 9). 
The base of the zoarium is quite wide ; the branches are arranged horizontally 
(fig. 19) ; the first bear radicells of consolidation, like small stilts (fig. 20) which 
separate all the branches from the substratum. A section (fig. 15) taken through 
these radicells shows that they are formed of ordinary zooecia curved as usual 
and which were probably deprived of ordinary polypides. 
We are not certain that the ovicell shown in figure 12 really belongs to this 
species; it is the only fragment found at this locality and the oeciostome is quite 
clearly preserved on it. 
Affinities.— The calcareous radicells are not rare. They have already been 
noted by Smitt, 1872, in Idmonea milneana D’Orbigny, 1839, by Kirkpatrick, 1888, 
in Idmonea radicata , and by Norman, 1909, in Idmonea ■ pedata. 
This species differs from Idmonea pedata Norman in its less salient fascicles 
and in having five zooecia (and not three) to a fascicle. 
