NORTH AMERICAN EARLY TERTIARY BRYOZOA. 337 



A-D. Schizoporella spinifera Johnston, 1S47. A-C. Lateral (A), oral (B) aud aboral (C) 

 face of the larva. D. Embryo. (A-D after Barrels, 1877.) cal, calotte (terminal bud) ; cd, 

 digestive cavity; co, corona; est, stomach: fc, ciliated cleft; fl, flagellum ; fo, oral face; /= 

 aboral face; mi, aboral mesoderru ; ing, oral (labial) mesoderm ; osi, orifice of internal sac; ph, 

 pharynx; plv, vibratile plume; RV, terminal bud; S=s, oral (vestibular) face; spa, palial fur- 

 row ; sc, inferior pigmented zone ; zs, superior pigmented zone. 



E-S. Schizobrachiella snnguinca Norman, 1SGS. 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 Calvet, 

 1900.) cal calotte (terminal bud) ; co, corona; d, vaginal diaphragm; ecto, oral ectocyst: epm, 

 mesodermnl thickening; fc, ciliated cleft; fit in, 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;spn, palial furrow; sgi, inferior glandular 

 system. H. Zooeria and ovicells, X 25. (After Hi neks, 1SSO.) I, J. Opercula, X 85. (After 

 Waters, 1S7S. ) K. Basal view of zooecium from which the basal wall has been removed, c. s., 

 compensation sac; op. gj., 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 zooecial 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 So. 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. Schizopodrdla (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, 1908.) 



Y-B'. Schizopodrdla (Schizoporella) nirea 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'. Schiznpodrella ( SchKoporella) 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 ovicell (oc) but of the numerous muscles 

 in this sac only about half of those in focus are drawn. It seems that the ovum (or) 

 passes into this sac which is tljen ruptured (r), and the ovum is pressed forward into the 

 ovicell, where it segments. The small oral galnds are shown (gl). After Waters, 1913.) 

 D'. Sketch showing a gigantic avicularium (arc) ; proy, proximal end of the zooecium, 

 into which the polypide extends, beneath the avicularium. (After Harrner, 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.) 



55899 19 Bull. 106 22 



