BRYOZOA. 175 
Phxnopora.] 
This form is easily distinguished from all the branching Clinton group species 
of the genus by the longitudinal arrangement of the mesopores. It is, however, 
especially in its internal structure, very similar to, and perhaps a descendant of, 
Escharopora (?) limitaris. Still, its branches are narrower and more rigid, and there 
is not that difference in the size of the central and marginal rows of zocecia that 
pertains to that Minnesota species. 
Formation and locality—Trenton limestone, Montreal, Canada, and Chimney Point, Vermont. 
Recently a fragment apparently identical with the eastern types of the species was collected at St. Paul, 
Minnesota, by the author, in the Galena shales, 
Collectors, Mr. T. C. Curry and Prof. Henry M. Seely. 
PHANOPORA .WILMINGTONENSIS n. Sp. 
PLATE XIII, FIGS. 22-26. 
Zoarium a simple lanceolate frond, straight or slightly curved, tapering to a 
point below, 40 to 100 mm. or more in length, 6 to 24 mm. wide, and 1.0 to 2.5 mm. 
thick at the center; edges acute, non-poriferous margin inconspicuous, surfaces 
gently convex, sometimes a little flattened on each side of the center, exhibiting, 
according to the width of the frond, from one to ten rows of low monticules. The 
latter occur at intervals of 2 or 3 mm., are usually arranged in rather irregular 
longitudinal and diagonal rows, and occupied by greater or smaller aggregations of 
mesopores and zoccia, the latter of slightly larger size than the average. Zoccial 
apertures subcircular or ovate, arranged in regular diagonally intersecting and 
transverse rows ; often, especially in the lower half of the zoarium, with the enclosing 
rim depressed at the ends, in which case they appear to be longitudinally confluent. 
Longitudinal interspaces depressed, generally with two small mesopores, one just in 
front of, the other immediately behind each aperture. Toward the center of the 
monticules the number of the mesopores in each interspace is gradually increased 
to four or more. Measuring lengthwise, about twelve apertures in a direct line 5 mm. 
long, and twenty-three or twenty-four of the transverse rows in the same distance ; 
diagonally, twenty, and transversely twenty-three or twenty-four in 5 mm. 
In tangential sections the base of the primitive cells is greatly elongate and 
bounded by subparallel sides and slightly oblique end walls. Very soon after, the 
anterior two-thirds is swollen and a curved hemiseptum thrown out from one side, 
which continues till it joins the opposite wall, thus enclosing the primitive aperture. 
Preceding this the walls are very thin, but now they add to their thickness by 
internal deposit. At the same time the aperture assumes a more rounded shape, the 
walls approach laterally so that each cell is, normally, in contact with six of its 
neighbors. Between these points there is a triangular open space or mesopore. 
