NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
337 
A-D. Schizoporella spinifera Johnston, 1847. A-C. Lateral (A), oral (B) and aboral (O) 
face of the larva. D. Embryo. (A-D after Barrois, 1877.) cal, calotte (terminal bud) ; cd, 
digestive cavity; co, corona; est, stomach; fc, ciliated cleft; fl, flagellum; fo, oral face; I=i 
aboral face; mi, aboral mesoderm; ms, oral (labial) mesoderm; osi, orifice of internal sac; ph, 
pharynx; plv, vibratile plume; R V, terminal bud; S=s, oral (vestibular) face; spa, palial fur- 
row ; zc, inferior pigmented zone ; zs, superior pigmented zone. 
E-S. Schizobrachiella sanguinea Norman, 1868. E, F. Larva from the left lateral face (E) 
and from the ventral face (F). G. Median sagittal section of the embryo. (E, F after Oalvet, 
1900.) cal, calotte (terminal bud) ; co, corona; cl, vaginal diaphragm; ecto, oral ectocyst; epm, 
' mesodermal thickening; fc, ciliated cleft; fnm, neuro muscular bundles; fs, superior fosette; one, 
central nervous organ of embryo ; pfse, nerve plexus under ectoderm : pplv, papilla of vibratile 
plume ; sga, superior glandular system ; si, internal sac ;spa, palial furrow ; sgi, inferior glandular 
system. H. Zooecia and ovieells, X 25. (After Hi neks, 1SS0.) I, J. Opercula, X 85. (After 
Waters, 1878.) K. Basal view of zooecium from which the basal wall has been removed, c. s., 
compensation sac ; op. gl., opercular glands ; p. m., parietal muscles ; r. rimule ; t, tentacles. L-S. 
Glandular system. (After Waters, 1892.) L. Gland-like body, X 500. M. Opercular and distal 
end; the gland-like bodies are shown in section, X 85. N. Same as M, showing (a) growth 
from tissue at the opercular end. The right gland-like body is shown in section and with an 
attachment to the zooec-ial wall, X 85. O. The prolongation of tissue shown in fig. N. has now 
grown into the median body (a) which lies diagonally across the upper part of the zooecium, 
X 85. P. The same, hanging from the center, attached merely by a fine cord, X 85. Q. Longi- 
tudinal section of a median body showing the refracting masses, X 250. R. Transverse section 
of the same, X 250. S. Nucleated cells of glands, X 500. 
T-X. Schizopoclrella ( Schizoporella ) unicornis Johnston, 1847. T. Free larva, lateral view. 
U. Oral face of same. V. Aboral face of larva. W. Ancestrula with terminal bud and two 
lateral buds, X 35. (T-W after Barrois, 1877.) X. Sketch showing the diagonal position of the 
zooecia, X 25. (After Waters, 190S.) 
Y-B'. Schizopoclrella ( Schizoporella ) nivea Busk 1884. Avicularian glands of the small 
avicularia. (After Waters, 1913.) The two glands separated, X 320 (Y) ; the same, X 100 (Z) ; 
glands united, X 320 (A') ; gland, X 320 (B'). 
C'-E'. Schizopoclrella ( Schizoporella ) linearis Hassall, 1841. C'. Two zooecia. X 50, 
figured near together but not in the same row, and placed together to save space. A sac- 
like structure (.sc) is shown at the base of each ovieell ( oc ) but of the numerous muscles 
in this sac only about half of those in focus are drawn. It seems that the ovum (ov) 
passes into this sac which is then ruptured (r), and the ovum is pressed forward into the 
ovieell, where it .segments. The small oral galnds are shown (gl). After Waters, 1913.) 
D'. Sketch showing a gigantic avicularium ( avc ) ; prox, proximal end of the zooecium, 
into which the polypide extends, beneath the avicularium. (After Harmer, 1902.) E'. 
Zooecium, showing the compensatrix (c.s.). The emargination of the frontal shield con- 
taining the sinus of the operculum enlarges as it passes through the thickness of the calcareous 
wall, so that its outline on the inner side of the frontal shield is represented by the line x. 
(After Harmer, 1902.) 
F'. Schizoporella gelida Waters, 1904. Interior, showing condyles (denticles), X 25. (After 
Waters, 1904.) 
G'. Schizoporella magniporata Nordgaard, 1906. Sketch, X 26, showing the distal ( tp ) and 
lateral dietellae. (After Nordgaard, 1906.) 
55S99— 19— Bull. 106- 
-22 
