NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
543 
TUBUCELLARIA PARVIPOROSA, new species. 
Plate 70, figs 1-4. 
Description. — The zoarium is articulated ; the segments arc cylindrical and very 
long. The zooecia are 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. 
Ill easurements. — Zooecia i , „ 
1/3=0.40 mm. 
Affinities. — The system of branching is the same as in Tubucellaria fallax; but 
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 Tubucellaria. vicksburgica 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 polvpide ? 
Occum'ence. — Middle Jacksonian: Baldock. Barnwell County, South Carolina 
(common). 
Cotypes. — Cat. No. 64182, U.S.N.M. 
TUBUCELLARIA FALLAX, new species. 
Plate 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. 
Measurements. — Zooecia j 
Peristomice 
7/3=1.10 mm. 
lz— 0.35 mm. 
Peristome= 0.20-0.25 mm. 
| Ovicelled zooecia=0.20 mm. 
(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 Tubucellaria fallax and T. parviporosa there 
are two pores in the vicinity of the external aperture, and the zooecia which bear 
