NORTH AMERICAN EARLY TERTIARY BRYOZOA. 499 



FIG. 140. Anatomy of ihe Keteporidae Smitt, 1867. 



fl!. oral glands; mp, parietal muscles; nir. retractor muscles of the polypide; s, septula ; 

 x/i. spiraii-.cn: /, tentacular sheath; r, vibrncula. 



A-C. Schizellozoon solmulcria Risso. 1S20. A. B. Anterior and posterior sides, X 25. < After 

 Waters, 1S92.) C. Detail of the peristomie showing the spiramen, the spines, and the slit of the 

 ovicell, X 75. (After Calvet, 1902.) 



D-G. Rctcpora ccUulosa 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, hut 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. Sclii;cllo.:ooit impcrnti Busk, 18X4. Hooting process, X 25, and section of the same, 

 X 12. (After Waters, 1888.) 



J-L. Rctepora anlarctica Waters, 1004. J. Calcareous section showing the internal (no) 

 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 zooeciuui. 

 X 85. L. Zooecium showing the oral (vaginal) glands (gl], and also the parietal muscles 

 (mi)). X 85. 



M-O. HippclJozoon Jiippocrcpis Waters. 1004. M. Section of zooeciuui 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 (oril) are also attached, X 85. N. Section showing the 

 lubular process (/6) below the operculum (o). X 250. O. Section of joint of oral spine, X 250. 

 (J-O after Waters, 1904.) 



Figs. P, Q. Rctcpora ccllitloxa Smitt. 1SC7. P. Section showing the gland-like sacks at the 

 side, X 85. Q. Double sack, X 250. ( P, Q after Waters, 1888. ) 



R. TrjipliyUo~oon nioniUfcra vnibnnata MacGillivary, 1885. Operculum wtih its muscular 

 attachments. (After MacGillivray, 1885.) 



S. T. Retepora tieaniana King, 1846 . S. A developing colony consisting of one. ancestrnla, 

 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 Rctcpora showing the zooecial and dorsal layer with the lines of 

 the vibices also visible, a, suboral pore entering the zooeeial chamber considerably lower down 

 than the aperture: or, avicularian chamber : or. ovicell: r. vibracula. This is a typical Rctcpora, 

 but is practically drawn from Retc/mm i-raxw Busk, X 85. (After Waters, 1904.) 



V, W. Two zoaria of Retepora natural size. (After Nordgaard.) 



