NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
755 
Fig. 244. — Family Tubuliporidae Johnston, 1838. 
A-D. Tttbulipora flabellaris Fabricius, 1780. A. B. Free larva and optical section. O. D. 
Aspect of tlie embryo at the beginning of the narrowing, drawing the projection more and more 
strongly from the mesodermic thickening and from the mantle, cd, Digestive cavity ; cm, 
triangular portion of the body cavity between tire fatty mass and the pharynx and the stomach; 
mt, mantle; mi, fatty mass; o, orifice of the gastrula ; s, oral face or from the vestibule. (A-D 
after Barrois, 1877. ) 
E-G. Tulmlipora plialangea Couch, 1844. E. Polypide detached from the cell. F. Aspect of 
the zoarium with its polypides evaginated. (E, F, after Milne-Edwards, 1838.) G. Degeneration 
of the fertile polypide (stage B), X 17. The tentacles have lost their distinct outlines, and 
are obviously degenerating. 
H. Stage B of Tulmlipora plumosa Thompson, 1847, the embryo consisting of two blastomeres. 
The caecum of the fertile polypide (which has not yet degenerated) is seen; f. and the corre- 
sponding structure to the left are probably the degenerating follicles of eggs which are not de- 
veloping. (After Harmer, 1S9S.) 
I-K. Tulmlipora serpens (Busk, Smitt, Hindis). I. Polypide detached from the cell. .T. 
Ciliated embryo. (After Smitt, 1865.) K. Formation of the secondary embryos, a, primary 
and secondary embryos; c, wall of the stomach; p, pharynx; R, large retractor muscle of the 
polypide; r, anus; t, tentacles; v, stomach. 
L-O. Tulmlipora plumosa Thompson, 1847. L. Fertile lobe, with one ovicell and the begin- 
ning of a second ovicell; from a bilobed colony (proximal ends of oldest zooecia at the bottom of 
the figure, obscured by foreign substance. M. Ovarian egg, in follicle (stage A). N. Decalcified 
preparation of an old ovicell (stage G) with nearly solid embryophore containing numerous sec- 
ondary embryos. The axial lobe of the embryophore ends in the oeciostome at o, and gives off 
another lyilie to the right. The main lateral lobe of the right side is only obscurely bifurcated ; 
that of its left side is divided into five lobes. Z, proximal part of the ovicell, corresponding with 
a zooecium. Greatest length of solid part of embryophore to tip of most projecting lobe, 2.5 mm. 
O. Orifices (apertures) of living zooecia. The terminal membrane lias been somewhat re- 
tracted. (L-0 after Harmer, 1898.) 
P-R. Mesonea radians Lamarck, 1816. P. An example, X 25, showing ovicells with oecio- 
stome ( oe ). Q. Section from the anterior to the dorsal surface of the zoarium, X 85. showing 
the lobes of the ovicell and the oeciostome (oc) as well as the polypides (p). The structure of 
the wall of the ovicell is seen at the left (st) with one or two rosette plates at the base of the 
broad pore tube. There is an outer membrane (m). R. Longitudinal section of the ovicell, cut 
parallel to the anterior and dorsal surfaces. (After Waters, 1914.) 
