JSTORTH AMERICAN EARLY TERTIARY BRYOZOA. 
257 
considered. We have studied a number of species with a faceted cryptocyst, notably 
M embraniporidra spissimuralis. It is not certain that the Cretaceous species are 
provided with onychocellaria, for these structures are perhaps interzooecial avi- 
cularia, of a special type now extinct. In the interior the polypidian tube is 
analogous to that in Aspidostoma Hincks, 1881; it is a thick- 
ening of the proximal border of the aperture. 
The species of the genus are : 
Euritina ( Eschara ) eurita D’Orbigny, 1852. 
Euritina welschi Canu, 1900. 
Euritina lata Canu, 1911. 
Euritina elongata Canu, 1911. 
Euritina intermedia Canu, 1911. 
Euritina ( Biflustra ) torta Gabb and Horn, 1862. 
Euritina ( Vincularia ) gracilis D’Orbigny, 1852. 
EURITINA TORTA Gabb and Horn, 1862. 
Plate 1, fig. 16. 
1862. Biflustra torta Gabb and Horn. Monograph of the Fossil 
Polyzoa of the Secondary and Tertiary formations of 
North America, Journal Academy of Natural Sciences, 
Philadelphia, ser. 2, p. 152, pi. 20, fig. 36. 
1901. Biflustra torta Ulrich, Maryland Geological Survey, Eocene, p. 
1909. Biflustra torta Weller, Cretaceous Faunas, Geological Survey 
p. 332. 
Fig. 68. — Genus Euri- 
tina Canu, 1900. 
Euritina ( Eschara ) eu- 
rita D’Orbigny, 1852. 
Zooecia with ovicells, 
X 20. 
. 214, pi. 60, fig. 7. 
of New Jersey, vol. 4, 
~ fAo=0.2omm. 
M easurements. — Opesia [ , . , „ 
r [fo=0.12-0.15 mm. 
Zooecia 
Lb= 
lz= 
0.10-0.45 mm. 
0.25-0.30 mm. 
The zoarium is bilamellar; the two lamellae are back to back and may be 
separated. The cryptocyst is deep and the two grooves which separate it from the 
mural rim are quite visible. 
The onychocellarium is straight, symmetrical, oval ; the beak is salient in front 
of the zooecial plane; there is no pivot. 
At the base of our figure there is a regenerated zooecium. 
“Although rather variable this is still to be counted as an easily recognized 
species. Ovicells occur but rarely, only four or five specimens out of fifty or more 
in my collection having any at all. They are cueullate often with a delicate longi- 
tudinal ridge across them and uniformly convex.” (Ulrich 1901.) 
Occurrence. — Lowest Eocene (Bryozoan bed at base of Aquia formation) : Upper 
Marlboro, Maryland (rare). 
Geological distribution. — Upper Cretaceous (Vincentown limesand) : Mullica 
Hill. Timber Creek, and Vincentown, New Jersey. 
Plesiotype. — Cat. No. 63778, U.S.N.M. 
55S99— 19— Bull. 106 17 
