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 crenulated 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 submediau triangular avicularium, with pivot. The 

 deep zooecia are almost entirely visible. The incomplete zooecia and the oral, 

 incomplete avicularia are very abundant. 



[A:= 0.09 mm. 

 Measurements. Apertura \ , 



Uffl=0.08mm. 



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 Holoporella orblcitlifera in its larger 

 and more scattered zooecia and in having four spines instead of two. 



It differs from Holoporella, pisifornris in its larger micrometric dimensions 

 and in the absence of a peristomice with simple or double apophysis. 



It differs from Holoporella 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.Czt. No. 64329, U.S.N.M. 



HOLOPORELLA PERISTOMARIA, new species. 



Plate 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- , . . 



U=0.06 mm. 



Affinities. The only specimen collected has been figured: although it bears 

 HO ovicell, it appears to us to be sufficiently characterized to be described. Mani- 



