NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
835 
This family offers the greatest resemblances to the Diaperoeciidae. It differs 
from it chiefly in the more constant form of the ovicells and in the presence of 
mesopores. 
This family includes a great number of zoarial forms classified by Gregory 
in his families of Petaloporidae and Zonatulae, in which the ovicell is identical. 
It includes also the forma Multicavea D’Orbigny, 1852. The ovicell of the latter 
and also that of Zono'pora of the same author have been discovered by Canu in 
the French Cretaceous. 
D 
Fig. 277. — Forma Multicavea D’Orbigny, 1852. 
A-F. Multicavea -magnified D’Orbigny,’ 1852. A, B. Zoaria, natural size. C. Transverse sec- 
tion of a branch, enlarged. D. Aspect of the zoarial surface, enlarged. E. Longitudinal section. 
(A-E, after D’Orbigny, 1852.) F. An ovicelled specimen from the Maastrichtian of Royan, 
France. 
I'he genera recognized by Gregory are only zoarial forms. Thus the form 
called Cavaria , with hollow zoarium, presents ovicells of Ascosoeciidae (as Para- 
scosoecicc consimilis Ulrich, 1882), of Leiosoeciidae (as P arlciosoecia jacksonica. new 
species), and Tretocycloeciidae (as Partretocycioecia exilis , new species). 
Moreover, the zoarial aspect called Zonopora results simply from the bifur- 
cation of the mesopores; it can therefore occur without importance in any family 
containing adventitous tubes. 
