NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
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Fig. 140. — Anatomy of the Reteporidae Smitt, 1867. 
gl, oral glands; mp, parietal muscles; mr, retractor muscles of the polypide; s, septula; 
up, spiramen; ts, tentacular sheath; v, vibraculn. 
A-C. Sch-izellozoon solanderia Risso, 1S20. A, B. Anterior and posterior sides, X 25. (After 
Waters, 1892.) C. Detail of the peristomie showing the spiramen, the spines, and the slit of the 
ovicell, X 75. (After Calvet, 1902.) 
D-G. Retepora cellulosa Smitt, 1867. D. The proximal part of an old colony cut across 
transversally. The superficial kenozooecial layer is seen. X 12. E. The same piece as shown 
in fig. D, but the transversally cut surface is seen. The three groups of small round aper- 
tures, almost in the center of the section, are intersected zooecial chambers, which on 
both sides are covered by kenozooecia, X 12. F. A part of the transverse section in Fig. E, 
more highly magnified. The separating walls furnished with uniporous septulae are seen 
between the kenozooecia placed above each other, X 40. (D-F after Levinsen, 1909.) G. Sec- 
tion showing vicarious avicularia with gland-like bodies. Each avicularium is connected through 
septulae with two zooecia, X 85. (After Waters, 1892.) 
H, I. Sehizellosoon imperati Busk, 1884. Rooting process, X 25, and section of the same, 
X 12. (After Waters, 1888.) 
J-L. Retepora antarctica Waters, 1904. J. Calcareous section showing the internal ( aa ) 
condyles (teeth) near the base of the operculum; also the lateral septula with “watch-glass” 
cover, X 85. K. Avicularian chamber with branches leading to the proximal end of the zooecium, 
X 85. L. Zooecium showing the oral (vaginal) glands (gl), and also the parietal muscles 
(mp), X 85. 
M-O. Hippellozoon Uippocrepis Waters, 1904. M. Section of zooecium showing the oper- 
culum (o), below which is the fleshy mass, with a tubular process from each side. To this 
fleshy mass the gigantic oral glands (ogl) are also attached, X 85. N. Section showing the 
tubular process (tb) below the operculum (o), X 250. O. Section of joint of oral spine, X 250. 
(J-O after Waters, 1904.) 
Figs. P, Q. Retepora cellulosa Smitt, 1867. P. Section showing the gland-like sacks at the 
side, X 85. Q. Double sack, X 250. (P, Q after Waters, 1SS8.) 
R. Tryphyllosoon monilifera umbonata MacGillivary, 1885. Operculum wtih its muscular 
attachments. (After MacGillivray, 1885.) 
S. T. Retepora , beaniana King, 1846 . S. A developing colony consisting of one ancestrula, 
two fully developed zooecia, and two developing zooecia, X 40. T. A somewhat older colony 
in which a root expansion of kenozooecia is already formed, X 17. (See figs. H, I.) (S. T after 
Levinsen, 1909.) 
U. Calcareous section of Retepora showing the zooecial and dorsal layer with the lines of 
the vibices also visible, a, suboral pore entering the zooecial chamber considerably lower down 
than the aperture; av, avicularian chamber; ov, ovicell; v, vibracula. This is a typical Retepora, 
but is practically drawn from Retepora ■ crassa Busk, X 85. (After Waters, 1904.) 
V, W. Two zoaria of Retepora natural size. (After Nordgaard.) 
