CORALS AND BRYOZOA. 
131 
e. Forms in which the carince of adjacent branches , on the cellulifcrous side , are connected 
by transverse scald. 
U N I T R Y P A, s. g., Hall. 1885. 
(See page 54.) 
Fenestella (Unitrypa) ACAULIS. 
PLATE LI, FIGS. 1-6. 
Fenestella (Hemitrypa) acaulis, Hall. Trans. Albany Institute, vol. x, abstract, p. 33. 18S1. 
“ ( Unitrypa) “ “ Report of State Geologist for 1885, advance sheets. Expl. pi. 51, 
figs. 1-15. 1886. 
Unitrypa conferta, Ulrich. Cont. Am. Pal., vol. i, No. 1, p. 17, pi. 1, figs. 8, 8a. 1886. 
Bryozoum infundibuliform, compact. Branches slender, width above a bifur¬ 
cation .20 to .24 mm., increasing to from .35 to .50 mm., the strength 
varying on different fronds, straight, angular when well preserved, 
rounded when worn, sometimes smooth, at other times nodose; nodes irregu¬ 
larly disposed, or in one or more longitudinal lines. Interstices usually 
narrower than the branches, but on some fronds wider. Dissepiments slender, 
width from .20 to .25 mm., angular or rounded, on the same plane or elevated 
above the branches, sometimes continuing across and coalescing with those 
of adjacent branches, forming irregular, continuous transverse elevations 
more prominent than the branches, about eight in the space of 5.50 mm. 
Fenestrules oval, length .40 to .50 mm., width usually from .20 to .25 mm., 
but on some fronds occasionally .35 mm. 
On the celluliferous face the dissepiments are rounded, very much depressed. 
Fenestrules narrower than on opposite face, length often three times the 
width. Cell apertures in two ranges, opening directly outward, oblique to 
the axis of the branch, twenty-four in the space of 5 mm., separated by less 
than one-half the diameter of an aperture: margins elevated, strongly in¬ 
denting the borders of the fenestrule, those of adjacent branches sometimes 
nearly in contact. Surface between ranges of apertures carinatecl; carinse 
.50 mm. in height, very thin below, expanding to a width of about .15 
mm.; carinse connected by scalse, the summits of which have a width of 
about .14 mm.; these extend downward till within a short distance of the 
branch, for half the distance obliquely toward the base, then abruptly bending 
