NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
611 
zooecia are completely erect, orbicular, quite scattered from each other ; the frontal 
is smooth and surrounded by from 4 to 6 large, widely spaced areolae. The aper- 
tura is ogival very finely crenidated with two minute cardelles placed quite low; 
the peristome is funnel shaped and bears four spines. The ovicell is hyperstomial, 
recumbent, salient, transverse, smooth; it opens very widely above the apertura. 
Very often the frontal bears a submedian triangular avicularium, with pivot. The 
deep zooecia are almost entirely visible. The incomplete zooecia and the oral, 
incomplete avicularia are very abundant. 
Measurements . — Apertura 
j/ux=0.09 mm. 
[/(?,= 0.08 mm. 
Variations . — It is quite rare that a zoarium dies when its superficial zooecia 
are completely formed (fig. 9). The most habitual aspect is that of figure 8; 
the oral avicularium is reduced to the state of a cicatrix of more or less depth; 
the spines are almost always absent and the incomplete zooecia are very abundant. 
The Cellepores are not always marred by fossilization ; they are often incom- 
pletely developed. 
Affinities . — This species differs from Iloloporella orbiculifera in its larger 
and more scattered zooecia and in having four spines instead of two. 
It differs from Iloloporella pisiformis in its larger micrometric dimensions 
and in the absence of a peristomiee with simple or double apophysis. 
It differs from Iloloporella separata in the absence of a large pedunculate 
avicularium between the superficial zooecia and in the presence of four spines 
and some areolae. 
Occurrence . — Vicksburgian (Marianna limestone) : West bank Conecuh River, 
Escambia County, Alabama (common) ; Murder Creek, east of Castlebury, Conecuh 
County, Alabama (rare) ; near Claiborne, Monroe County, Alabama (rare) ; Salt 
Mountain, 5 miles south of Jackson, Alabama (common). 
Cotypes. — Cat. No. 64329, U.S.N.M. 
HOLOPORELLA PERISTOMARIA, new species. 
Pfate 102, figs. 5, 6. 
Description . — The zoarium is a small, irregular mass. The superficial zooecia 
are erect, tubular; the frontal is convex, surrounded by some large areolae. The 
apertura is oval, the poster being very concave; it is surrounded by a very long 
peristomie , sometimes fissured in front; the peristome is more or less thick, accord- 
ing to its proximity of the apertura. The deep zooecia have a small avicularium 
on their peristome. The marginal zooecia are recumbent, somewhat elongated, 
very convex; their frontal is terminated by an aviculiferous beak, salient and not 
symmetrical. 
Measurements . — Apertura 
\ha= 0.07 mm. 
I7'i=0.06 mm. 
Affinities . — The only specimen collected has been figured; although it bears 
no ovicell, it appears to us to be sufficiently characterized to be described. Mani- 
