580 
BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
PERIGASTRELLA OVOIDEA Canu and Bassler, 1917. 
Plate 73, figs. 2-4. 
1917. Perigastrella ovoidea Canu and Bassler, Synopsis of American Early Tertiary Gheilo- 
stome Bryozoa, Bulletin 96, United States National Museum, p. 68, pi. 6, fig. 8. 
Description. — The zoarium incrusts shells. The zooecia are distinct, elongated, 
large, ovoid ; the frontal is very convex, bordered by very small areolar pores and 
formed of a very finely granular pleurocyst almost smooth, The apertura, almost 
invisible exteriorly, is trapezoidal and oblique ; the peristomie is deep ; the peristome 
is very oblique and bears six to eight spines; it is sometimes interrupted in front, 
but more often it bears a salient mucro, oblique or erect, hiding more or less the 
apertura; there is a small lyrula in the apertura. The ovicell is small, salient, 
globular, almost entirely detached from the distal zooecium ; it is hyperstomial and 
recumbent; its frontal is finely granular like the zooecia. The ancestrula is very 
small, but identical in form with the other zooecia. 
Measurements. — Apertura 
j ha= 0.05 mm. 
Ua=0.0'8-0.10 
mm. 
Zooecia 
Lz= 0.75-0.80 mm. 
lz= 0.50 mm. 
Affinities. — This beautiful species is quite recognizable by its very large zooecial 
convexity. It differs from Perigastrella semierecta Koschinsky, 1885, in the presence 
of spines and in its somewhat larger dimensions. 
It differs from Perigastrella oscitans in its very small and nearly invisible 
areolae, its large frontal convexity, and its peristomice, three times smaller, and 
in its oral lyrula. 
It also resembles the ancestrular zooecia of Perigastrella cycloris Gabb and 
Horn, 1862, but differs in the apertura, which bears a lyrula and no cardelles. 
Occurrence. — Middle Jacksonian: Fut aw Springs, South Carolina (common). 
Upper Jacksonian (Ocala limestone) : Plant System Railroad wharf at Bain- 
bridge, Georgia (common) ; Old Factory, 1^ miles above Bainbridge, Georgia 
(rare) ; Red Bluff, on Flint River, 7 miles above Bainbridge, Georgia (rare) ; west 
bank Sepulga River, Escambia County, Alabama (rare) ; Chipola River, east of 
Marianna Jackson County, Florida (very rare). 
Vicksburgian (Marianna limestone) : Well, Escambia County, Alabama. 
Cotypes. — Cat. No. 62613, U.S.N.M. 
PERIGASTRELLA MAXILLA, new species. 
Plate 73, figs. 5-7. 
Description. — -The zoarium incrusts shells and other bryozoa. The zooecia are 
distinct, short, ovoid, erect; the frontal is very convex, almost smooth, surrounded 
by minute areolae, revealed only by some scarcely visible roughnesses. The aper- 
tura is deep, oblique, trapezoid, with a straight or somewhat convex proximal 
border; the peristomie is tubular, large; it is terminated by a peristome with 
usually eight spines and by a very large, rounded, salient, erect mucro, exposing 
to view the apertura and almost invariably depressed on the frontal. The ovicell 
