NORTH AMERICAN EARLY TERTIARY BRYOZOA. 543 



TUBUCELLARIA PARVIPOROSA, new species. 



Plate 70, figs 1-4. 



Description. The zoarium is articulated; the segments are cylindrical and very 

 long. The zooecia art- much elongated, distinct, fusiform ; the frontal is convex 

 and covered with small closely arranged pores; the peristomiale occupies the upper 

 fourth of the zooecia and is separated from the frontal by a small furrow. The 

 peristome is round, little thickened, salient, arranged obliquely or normally on the 

 segment. The ascopore is situated on the frontal below the peristomiale. The 

 ovicelled zooecia have a much larger external aperture. 



-., . (.3=1.30 mm. Peristome=0.22 mm. 



Measurements. Zooecia i , 



1/2=0.40 mm. 



Affinities. The system of branching is the same as in Tulnn-cllaria fall in-; lut 

 T. parviporosa is distinguished from that species by its much smaller frontal pores 

 and by its greater zooecial length (1.30 mm. instead of 1.10 mm.). 



It differs from Tuhucellnria vicksbwrgica in its smaller pores, its less zooecial 

 length (1.30 mm. and not 1.40 mm.), and in its system of branching not borne on 

 a large calcareous process. 



"We. have observed a closed zooecium in which only the ascopore persists. What 

 could be its physiologic use in the absence of the rjolypide ? 



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

 ( common ) . 



Cotypes.Cat. Xo. 64182, U.S.N.M. 



TUBUCELLARIA FALLAX. new spceies. 



rinte 70, figs. 5-10. 



Description. The zoarium is articulated; the segments are cylindrical and 

 short. The zooecia are elongated, distinct, fusiform; the frontal is convex and 

 covered with polygonal pores: the peristomiale occupies the upper fourth of the 

 zooecia and is not separated from the frontal. The peristome is round, thin, salient, 

 and arranged very obliquely to the segment. The ascopore is situated on the frontal 

 below the vestibular area. The ovicelled zooecia have a much larger external 



aperture. 



7",? = 1.10 mm. 

 Measurements. Zooecia 7s=0.35 mm. 



Peristome=0.20-0.25 mm. 



I Ovicelled zooecia=0.20 mm. 

 Peristomice , , , ,. 



(( ordinary zooecia=0.12 mm. 



Variations. The articulation in the American species is rather different from 

 that which we have observed on the recent forms. On the latter, in the immediate 

 neighborhood of the peristome, there is a large pore or sort of chitinous joint which 

 maintains the upper segment. On Tubucrllnria falla-x and T. parriporosa there 

 are two pores in the vicinity of the external aperture, and the zooecia which bear 



