590 
BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 
Genus SCHIZOBATHYSELLA Canu and Bassler, 1917. 
1917. Schizobathysella Canu and Bassler, Synopsis of American Early Tertiary Cfieilo- 
stome Bryozoa, Bulletin 96, United States National Museum, p. 69. 
The apertura presents on its straight proximal border a small linear rimule. 
The ovicell is recumbent and opens widely above the apertura. The frontal is a 
tremocyst. The peristomie is greatly expanded and is interrupted in front by an 
immense incomplete spiramen. The avicularium is vibraculoid. 
Genotype. — Schizobathysella saccifera Canu and Bassler, 1917. Jacksonian. 
This genus differs from Mastigophora only in the nature of the peristome, 
which is much more salient and interrupted in front by a pseudo-spiramen. 
It differs from 'Gigantopora Ridley, provided also with a spiramen, in the dif- 
ferent form of the operculum, and in the smooth frontal of the latter. 
To Jullien the spiramen seemed part of the hydrostatic apparatus. Here it 
appears to us as in rapport with the extrusion of the larvae. 
SCHIZOBATHYSELLA SEMILUNATA, new species. 
Plate 74, figs. 4-6. 
Description. — The zoarium incrusts shells. The zooecia are elongated, distinct, 
swollen, elliptical; the frontal is very convex and formed of a tremocyst with 
numerous pores in quincunx. The peristome is thin, irregular, distally laciniate; 
the peristomie is long and recumbent on the distal zooecia ; the apertura is semi- 
lunar; the anter is ogival and the poster straight; there are two small cardelles 
quite low. The spiramen is elliptical, transverse, much larger than the peristomice. 
A small, round avicularium near the spiramen. 
Measurements. — Apertura 
„ . \Lz= 0.60-0.70 mm. 
ZlOOCClcl ) 7 rv OA a A A 
\lz—0. 30-0.40 mm. 
\ha— 0.10 mm. 
\la= 0.12 mm. 
Variations. — The spiramen is not always complete ; the transversal arch which 
separated it from the peristomice is not always formed, but the lateral walls of 
the peristomie are always salient. The appendages which ornament superiorly 
the peristome are analogous to those of Galeopsis rabidus Jullien. 1903. Accord- 
ing to the French author these are the spines more or less united among them- 
selves. 
Affinities. — This species differs from Galeopsis verrucosa and Galeopsis 
erinaceus in the replacement of the frontal tuberosities by tremopores and in the 
semilunar and not elliptical form of the apertura. 
Occurrence. — Middle Jacksonian: Wilmington, North Carolina (rare); 31- 
miles north of Grovania, Georgia (very rare). 
Cotypes.— Cat. No. 64205, U.S.N.M. 
SCHIZOBATHYSELLA SACCIFERA Canu and Bassler, 1917. 
Plate 74, figs. 7, 8. 
1917. Schizobathysella saccifera Canu and Bassler, Synopsis of American Early Tertiary 
Cheilostome Bryozoa, Bulletin 96, United States National Museum, p. 70, pi. 6, fig. 7. 
Description. — The zoarium incrusts shells. The zooecia are distinct, elon- 
gated, irregularly elliptical; the frontal is convex and formed of a tremocyst with 
