NORTH AMERICAN LATER TERTIARY AND QUATERNARY BRYOZOA. 
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corner. C. Details of the aperture. (After D’Orbigny, 1852.) D. Portion of a recent zoarium, X 20, 
with several ovicelled zooecia. The operculum closes the aperture. E. Extremity of a zoarium. 
F. Transverse section. (E, F, after Manzoni, 1877.) G. Operculum, X 85. (After Waters, 1878.) 
H-J. Mynozoum coarctatum Sans, 1850. H. Transverse section. (After Smitt, 1868.) I. Oper¬ 
culum, X 85. J. Mandible, X 85. 
K-O. Mynozoum subgracile D’Orbigny, 1852. K. Portion of a zoarium with avicularia, X 25. 
L. Section of tissue, X 25, showing the polypides in position, the covering integument (a=ectocyst) 
over the inner one (6); also the long pore tubes which in various places have a disk separating the con¬ 
tents on the two sides of the disk. The oral diaphragm is seen as withdrawn. M. Section through 
polypide, X 85, showing: dm, the diaphragm; op, the operculum, with dotted lines to show the position 
when partly open; d, disks in the pore tubes. N. Covering integument (a), X 85. 0. End of pore 
tube, X 500, showing the covering integument (a) and the inner one ( b ). It contains some cellules of 
mesenchymatous tissue; P. Operculum X 85; Q. Mandible, X 50. (1-2 after Waters, 1900.) 
Family MYRIOZOIDAE Smitt, 1868. 
The frontal is thick and bears a tremocyst with tubules. Uniporous septulae 
or dietellae are present. The avicularia are adventitious and bear a pivot. The 
ovicell is hyperstomial not adjacent to the zooecium and lodged in a nichelike 
depression of the distal zooecium. 
According to Levinson the genera of this family are as follows: 
Haswellia Busk, 1884 (referred to the Galeopsidae by us). 
Geyhyrophora Busk, 1884 (Galeopsidae). 
Myriozoella Levinsen, 1909. 
Myriozoum Donati, 1750. 
G 
E 
Fig. 35.—Genus Myriozoella Levinsen, 1909. 
A-G. Myriozoella Crustacea Smitt, 1868. A. Zooecia with peristomes and with cancellated frontal 
B. Zooecia showing the ovicell. C. Zooecia without peristome, X 26.5. (A-C, after Smitt, 1868.) 
D. Zooecia. X 26.5, much calcified, in which the frontal is not cancellated. E. Ancestrula and ances- 
trular zooecia, X 50. F. Operculum, X 85. G. Mandible, X 250. (E-G, after Maters, 1900.) 
12184—23—Bull. 12! 
13 
