NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
451 
METROCRYPTA BUCCULENTA Canu and Bassler, 1917. 
Plate 58, figs. 1-10. 
1917. Metrocrypta bucculenta Canu and Bassler, Synopsis American Early Tertiary Cheilo- 
stome Bryozoa, Bulletin 96, United States National Museum, p. 49, pi. 5, fig. 2. 
Description. — The zoarium is free, cylindrical, bifurcated. The zooecia are 
elongated, large, little distinct; the frontal is convex, porous, formed of a tremo- 
cyst placed on a thick olocyst. The peristoitiice is somewhat elongated, oval, its 
lower point formed of a wide rimule-spiramen ; the peristomie is somewhat salient; 
the apertura (interior) is much smaller, orbicular, very oblique. The oral avieu- 
larium is very rare; it is quite large, prominent, triangular, adjacent to the peristo- 
mice, provided with a pivot placed very low. 
Measurements. — Peristomice \hpe= 0.30-0.35 mm. j Apertura ha= 0.15 mm. 
, (exterior) \lpe= 0.30 mm. I (interior) ?<z=0.15 mm. 
„ . fZs=1.00mm. 
Zooeci&) 7 qq 
iZz=1.23mm. 
Variations. — The zooecia are sometimes distinct and separated by a prominent 
thread (fig. 3). The peristomie (fig. 6) is very wide and in proportion with the 
size of the peristomice; the apertura being small, we are ignorant of the use of 
the exaggerated development of this tube. The exterior and frontal walls are very 
thick (figs. 6, 7) ; but the interior walls are thin and very fragile (fig. 10). In the 
interior the apertura is almost invisible, because it is almost perpendicular to the 
plane of the frontal (fig/ 10). 
We have observed some interzooecial swellings; they are globular, porous, pro- 
vided with an orbicular orifice (fig. 9). They are superposed on the tremocyst 
and always appear in connection with a peristomie (figs. 2, 8). Can this be the 
ovicell ? 
Occurrence. — Middle Jacksonian (Castle Hayne limestone) : Wilmington, North 
Carolina (common). 
Cotypes. — Cat. No. G2598, U.S.N.M. 
Genus OCHETOSELLA Canu and Bassler, 1917. 
1917. Ochetosella Canu and Bassler, Synopsis American Early Tertiary Cheilostome 
Bryozoa, Bulletin 96, United States National Museum, p. 49. 
The ovicell is hyperstomial and deeply imbedded in the distal zooecium. The 
rimule-spiramen is replaced by a small canal supported by a peristomial projection. 
The frontal is an olocyst perforated laterally by some areolae and covered by a 
uniform pleurocyst. 
Genotype. — Ochetosella jacksonica Canu and Bassler, 1917. 
Range.- — Claibornian, Jacksonian. 
At first glance, this genus appears close to P al/micellaria, but this is an error. 
The large avicularian mucro of that genus is replaced here by a small canal which 
is evidently the equivalent of the rimule-spiramen of the other genera of the family 
