NORTH AMERICAN EARLY TERTIARY BRYOZOA. 579 



On the well-preserved specimens (notably those from Wilmington), by inclining 

 the preparation, we can see in the peristomie two or three salient denticles of whose 

 physiologic significance we are ignorant. 



The frontal is often smooth (fig. 17). 



The orifice of the ovicelled zooecia has somewhat the aspect of a human mouth 

 opened to yawn. 



Affinities. This species is distinguished from Perigastrella elegans l>y its large 

 general dimensions and the absence of three rows of areolar pores. 



It is distinguished from Perigastrella ovoidea in the elliptical form of its 

 zooecia, its lesser zooecial length (Zs=0.70 and not 0.80 mm.), its less convex 

 frontal, its wider and larger ovicell with two quite visible lamellae. 



It is distinguished from Pemgaxtrella plana in its smaller micrometric dimen- 

 sions (fe = 0.40 and not 0.50-0.60 mm.) and in its pleurocyst, which is complete 

 instead of being lateral only. 



Occurrence. Lower Jacksonian (Moodys marl) : Jackson, Mississippi (rare). 



Middle Jacksonian: Wilmington, North Carolina (common); 3} miles south 

 of Perry, Georgia (rare) ; 12 miles southeast of Marshallville. Georgia (rare) : Rich 

 Hill, Crawford County, Georgia (rare) ; Eutaw Springs. South Carolina (rare) ; 

 one-half mile southeast of Georgia Kaolin Company Mine, Twiggs County. Georgia 

 (rare) ; 17 miles northeast of Hawkinsville, Georgia. 



Upper Jacksonian (Ocala limestone) : West bank of Scpulga River, Escambia 

 County, Alabama (rare) ; old factory. H miles above Bainbridge, Georgia (rare). 



f'ofypes. Cat. No. 64196, U.S.N3L 



PERIGASTRELLA ELEGANS, new spcciea. 



Plate 73, fig. 1. 



Description. The zoarium incru^ls shells. The zooecia are distinct, a little 

 elongated, small, elliptical; the frontal is convex and surrounded by two or three 

 rows of round or triangular areolar pores; it is formed of a very finely granular 

 pleurocyst. The apertura is deep, trapezoid ; the peristome is complete, thin, salient : 

 its inferior lip is a very salient mucro. hiding somewhat the apertura or depressed 

 on the frontal. The ovicell is very small, little salient, and formed of a pleurocyst 

 and an olocyst which are distinct from each other. 



Aa=0.08mm. . \ .2=0.55 mm. 



' cia lZ,=0.30-0.35 mm. 



Affinities. This elegant species much resembles PerigaxtreUa oscitans in the 

 absence of decided characters and appears to be a minor variety of it. It differs 

 from it in its much smaller micrometric dimensions, less than 0.55 mm., in its 

 smoother ovicell, and its three rows of areolar pores. 



Occurrence. Middle Jacksonian: Baldock, Barnwell County, South Carolina 

 (rare). 



Holotype.Cnt. No. 64197. U.S.N.M. 



