NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
463 
SMITTINA EXIGUA, new species. 
Plate 59, figs. 17-19. 
Description . — The zoarium is free, bilame] I ar with flat or undulated fronds; 
the lamellae, back to back, are separable. The zooecia are elongated, distinct, 
elliptical; the frontal is convex bordered by a line of areolar pores; the pleurocyst 
is porous with short interareolar costules. The apertura (interior) is transverse, 
semilunar with a proximal border very little convex; the peristomice is elongated, 
deformed interiorly by the oral avicularium; the lyrula is very small and pointed. 
The ovicell is small, much imbedded in the distal zooecia ; the frontal area is quite 
fragile. The median avicularium is very small, elliptical with pivot. 
Measurements . — Peristomice 
J A/><?=0.14 mm. 
\lp'e— 0.12 mm. 
Zooecia 
1 7.3=0.60-0.80 mm. 
l/s=r0.30-0.32 mm. 
Apertura 
\ha— 0.12 mm. 
1^=0.13-0.14 mm. 
Variations . — Like all the species with porous pleurocyst, this one has some 
zooecia of quite variable aspect; even in fossilization the pores are closed and the 
zooecia appear absolutely smooth. 
Some closed zooecia, in which the apertura is replaced by a simple pore, 
appear quite frequently ; they never have an avicularium. Their physiologic role is 
unknown. 
Affinities . — This species differs from Smittina strombechi Reuss, 1865, in its 
larger micrometric dimensions (Zs= 0.60 mm. and not 0.44 mm.), its porous and 
not costular pleurocyst, and in its smaller ovicell. 
It differs from Smittina sordida in its pleurocyst, which is porous and not 
granular, and in the absence of all frontal avicularia. 
Certain variations of Poreila portentosa assume somewhat the aspect of this 
species, which differs, however, in the pleurocyst and nontremocystal frontal and 
in the nonbeaded peristome. 
Occurrence . — Middle Jacksonian: Eutaw Springs, South Carolina (rare): 
Baldock, Barnwell County, South Carolina (rare) ; 34 miles west of Grovania. 
Georgia (very rare) ; Rich Hill, Crawford County, Georgia (rare) ; 4 mile south' 
east of Georgia Kaolin Company Mine, Twiggs County, Georgia (very rare). 
Cotypes .— Cat No. 64122, 64131, U.S.N.M. 
SMITTINA STEOMBECKI Reuss, 1865. 
Plate 59, figs. 12-14. 
1865. Lepralia stromlbecki Reuss, Die Foraminifera, Anthozoen unci Bryozoen ties deutsclien 
Septarienthones, Denkschriften der k. Akacl. der wissenschaften Wien, vol. 25, 
Abth. 1, pi. S, fig. 12. 
Description . — The zoarium incrusts shells and bryozoa. The zooecia are small, 
elongated, fusiform, separated by a furrow or by a salient thread; the frontal is 
somewhat convex and bordered laterally by a line of small areolae; the pleurocyst 
is costular on the borders, apparently smooth in the middle, but actually porous 
