330 THE PALEONTOLOGY OF MINNESOTA. 
(Ceramoporella interporosa. 
CERAMOPORELLA INTERPOROSA, ”, Sp. 
PLATE, XXVIII, FIG. 12. 
All the Minnesota examples seen are thin crusts upon foreign bodies, but in the 
Cincinnati rocks the species often forms large masses by superposition of numerous 
layers. The zocecial apertures are larger, more direct, and comparatively wider than 
in C. distincta Ulrich, with an average of ninein 3 mm. Fig. 12 represents the 
usual appearance of the surface. Sometimes the lunarium is better distinguished 
from the rest of the posterior hood than shown in the figure. The mesopores are 
always numerous and generally more equally distributed around the zocecia than in 
other species of the genus. 
Formation and locality.—In Minnesota the species has been noticed only in the Galena shales of 
Goodhue county. At Cincinnati, Ohio, the same species apparently is not uncommon in the lower 300 
feet of strata. 
Mus. Reg. No. 7647. 
Genus DIAMESOPORA, Hall. 
Diamesopera, HALL, 1852, Pal. N. Y., vol. ii, p. 158 (not defined); Pal. N. Y., vol. vi, p. xv, 1887: 
ULRICH, 1890, Geol. Surv. Ill., vol. viii, pp, 380, 467. 
Celoclema, ULRICH. 1882. Jour. Cin. Soc. Nat. Hist., vol. v (not defined). 
Zoaria ramose, branches hollow, lined internally with a striated epitheca. In 
other respects very much like Ceramoporella and Ceramophylla. 
This name stands for an easily recognized division of the Ceramoporide. The 
genus may be more convenient than natural, yet I must confess that the evidence 
so far gathered points rather to an opposite conclusion. The species next described 
is the earliest known. Several occur in the Cincinnati rocks, but it is not till we 
come to the Niagara that the genus has its greatest development, both in the way 
of species and individuals. 
DIAMESOPORA TRENTONENSIS, ”. Sp. 
PLATE XXVIII, FIG. 14. 
Zoarium consisting of small hollow branches varying from 1.5 to 3.5 mm. in 
diameter; thickness of zoarium 0.4 to 0.8 mm.; axial tube varying in diameter, the 
epithecal lining not observed. Small maculwe sometimes present. Zocecial aper- 
tures oval, about their diameters apart, arranged sometimes regularly in diagonally 
intersecting rows, at other times as shown in fig. 14; averaging nine in 3 mm. 
When regularly arranged they are set into obliquely depressed subrhomboidal areas, 
