NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
549 
trary, the frontal tubules which are much developed about the ascopore; this is a 
fundamental difference. We are also ignorant of the physiological purpose of the 
development of the peristomial tubules. 
The length of the tubules is always very variable, as can be noted on the figured 
sections (figs. 6, 7). 
We have been rather fortunate in reconstructing a part of the zoarium, the 
dimensions of which ought to 
attain about four or five centi- 
meters in length. 
It is very easy to distinguish 
this species from all known 
forms. 
We have not had the chance 
to discover the ovicell in the 
eight sections which have been 
studied. 
Occurrence. — Middle Jack- 
sonian: Lenuds Ferry, South 
Carolina (common). 
Cotypes. — Cat. No. 64187, 
U.S.N.M. 
Genus TUBIPORELLA Levinsen, 
1909. 
1909. Tubiporella, Levinsen, Mor- 
phological and System- 
atic Studies on Cheilosto- 
matous Bryozoa, p. 305. 
A membraneous opercular 
valve. A vestibular arch, each 
zooecium with one or two avicu- 
laria at the height of the asco- 
pore. The colony occurs as a 
free, foliaceous expansion with a 
single layer of zooecia (Levin- °f zooecium, enlarged. B. Zoarium, natural size. C. Dor- 
sal side showing radical tubes. (A-C after Busk, 1884.) 
Genotype. — Tubiporella ( Lepralia ) magnirostris MacGillivray, 1882. 
Range. — Miocene — Recent. 
Genus SIPHONICYTARA Busk, 1884. 
1884. Siphonicytara Husk, Report on the Polyzoa collected by PI. M. S. Challenger, p. 101. 
Busk, in 1884, placed in this family his new genus Siphonicytara. specimens 
of which have never been found since and for which reason it has not been possible 
to make supplemental studies. His original description and figures follow. 
Fig. 162. — Genus Siphonicytara Busk, 1884. 
A-C. Siphonicytara serrulata Busk, 1884. A. Frontal side 
