440 
BULLETIN 106, UNITED STATES NATIONAE MUSEUM. 
SCHIZEMIELLA CLAIBORNICA Canu an<l Bassler, 1917. 
Plate 14, figs. 2-4. 
1917. Schizemiella claibornica Canu and Bassler, Synopsis American Early Tertiary 
Cheilostome Bryozoa, Bulletin 96, United States National Museum, p. 47, pi. 4, fig. 9. 
Description— The zoarium is free, bilamellar, with inseparable lamellae. The 
zooecia are indistinct; the frontal is thickened, little convex, formed of a tremocyst 
with large, irregular tubules placed on a thin olocyst with very small pores in 
quincunx. The apertura is formed of an ogival anter and a concave poster with 
a very wide rimule; the peristomice is elongated, embedded, with a very wide, 
irregular rimule-spiramen. The ovicell is liyperstomial and opens largely into the 
peristomie; it is little globular, hardly salient; covered by a smooth or perforated, 
very fragile wall; the peristomice is elliptical and transverse. The avicularium is 
triangular, the point directed above, adjacent to the peristomice which it deforms, 
provided with a pivot. 
Measurements. — Peristomice \hpe= 0.20 mm. Apertura j/>a=0.12 mm. 
(exterior) [lpe= 0.14-0.16 mm. (interior) \la=0.11 mm. 
Zooecia \Lz= 0.54 mm. 
(interior) Us =0.30 mm. 
Variations. — In the interior the tremopores are regularly placed in quincunx; 
on the exterior they are very irregularly disposed, larger and less numerous. 
The frontal of the ovicell is so fragile that we are unable to get an exact idea 
of it from our few specimens. This organ requires further examination. 
The rimule of the peristomice is very irregular. In reality the form of the 
apertura belongs (fig. 4) to the group of very typical Schizoporella , and the oper- 
culum ought to be chitinized enough to sufficiently insure the opening of the com- 
pensatrix by itself. 
Occurrence. — Claibornian (Gosport sand) : Claiborne, Alabama (rare) ; 1 mile 
southwest of Rockville, Clarke County, Alabama (rare) ; Gopher Hill, Tombigbee 
River, Alabama (rare). 
Claibornian (Cook Mountain formation) : Moseleys Ferry, Caldwell County, 
Texas (rare). 
Cotypes. — Cat. No. 62595, IT.S.N.M. 
Genus METRADOLIUM Canu and Bassler, 1917. 
1917. Metradolium Canu and Bassler, Synopsis American Early Tertiary Cheilostome 
Bryozoa, Bulletin 96, United States National Museum, p. 47. 
The ovicelled zooecia, different in form from the others, have a peristomice 
in the form of a lunar crescent without rimule-spiramen. The frontal is a tremo- 
cyst with tubules. 
Genotype.- — Metradolium dissimile Canu and Bassler. 1917. Jacksonian. 
Eschara tuberosa Reuss. 1866, of the Stampian of Germany, belongs without 
doubt to this genus. 
