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NORTH AMERICAN LATER TERTIARY AND QUATERNARY BRYOZOA. 191 
by very small areolar pores. There are often one or two avicularia in the vicinity 
of the apertura. On the inner side the zooecia are hexagonal or fusiform, termi¬ 
nated by a small orbicular pore or covered with large pores. 
Genotype. — Fedora edwardsi Jullien, 1882. 
Range .—Lutetian to Recent. 
The known species of this genus are as follows: 
Fedora edlcardsi Jullien, 1882. Recent (Atlantic). 
Fedora ( Stichoporina ) simplex Kirkpatrick, 1890 (not Koschinsky, 1885). 
Recent (Indian Ocean). 
Fedora ( Mamillopora ) smithi Calvet, 1907 (possibly F. persimplex Neviani, 
1895). Recent (Atlantic). 
Fedora ( Discofiustrellaria ) dactylus D’Orbigny, 1852. Lutetian. 
Fedora ( Stichoporina) simplex Koschinsky, 1885 ( = Stichoporina reussi Canu, 
1907). Lutetian. 
Fedora ( Stichoporina ) protecta Koschinsky, 1885. Lutetian, Jacksonian. 
Fedora ( Kionidella ) excelsa Koschinsky, 1885. Lutetian, Priabonian. 
Fedora (Stichoporina) crassilabris Koschinsky, 1885. Lutetian. 
Fedora ( Cupularia ) bidentata Reuss, 1869. (See Waters, 1919.) Priabonian. 
Fedora ( Kionidella ) obliqueseriata Koschinsky, 1885. Lutetian. 
Fedora ( Stichoporina) persimplex Neviani, 1895. Plaisancian. 
Fedora ( Lepralia) minutissima Sequenza, 1880. Helvetian. 
Genus MAMILLOPORA Smitt, 1873. 
1872. Mamillopora Smitt, Floridan Bryozoa, pt. 1, Kongl. Svenska Vetenskaps Akademiens Hand- 
lingar, vol. 10, no. 11, p. 33. 
Oral aperture large (0.12 mm.), contracted at each side. Primary zooecium 
erect, surrounded by six similar zooecia. Only unilaminate, showing the position 
of the zooecia on the under surface. (Waters.) The zoarium is cupuliform. The 
apertura is elliptical with two submedian cardelles. Avicularia are present. The 
ovicelled zooecia are much larger; their apertura is not transverse. The zooecia 
and their inner side are covered with tuberosities. 
Genotype. — Mamillopora cupula Smitt, 1872. 
The genotype of the genus is incompletely known. 
We have had the good fortune to secure some recent specimens of Mamillopora 
dredged in the Gulf of Mexico. The species appears to be new, but it shows some 
interesting facts on the structure of the genus. It differs from Mamillopora cupula 
Smitt, 1872, in having a much smaller and nonbilobed ovicell, in the presence of a 
peristomial avicularium instead of an interzooecial one, and in having analogous 
apertures on the ovicelled zooecia. Our specimens were unfortunately insufficient 
for a complete study, but nevertheless we have observed the following points: 
1. The ovicell is closed by the operculum. The operculum of the ovicelled 
zooecia is identical with the operculum of the other zooecia but often somewhat 
higher. 
2. On the inner, noncellular (superior) side each tuberosity is a pyriform avi¬ 
cularium in which the opesium, which is elliptical and without pivot, bears a small 
semielliptical mandible. The mandibles are quite variable in dimensions, as some 
are small and others are large. 
