186 
BULLETIN 125, UNITED STATES NATIONAL MUSEUM. 
So far as known this family is not represented in the American Tertiary, but 
its species, on the contrary, are of common occurrence in the Miocene and Pliocene 
of Europe. The larva in all of these genera is unknown and their classification 
necessarily remains doubtful. 
Genus MYRIOZOUM Donati, 1750. 
1750. Myriozoum, Donati, Stagie della storia naturale dell’ Adriatico. 
The zoarium is free, cylindrical, and arborescent. Septulae are present. 
Sixteen tentacles. 
Genotype .— Myriozoum ( Millepora) truncaturn Pallas, 1766. 
Range. —Helvetian-Recent. 
Genus MYRIOZOELLA Levinsen, 1909. 
1909. Myriozoella Levinsen, Morphological and Systematic Studies on the Cheilostomatous Bryozoa, 
p. 297. 
The zoarium is incrusting. Dietellae are present. Fifteen tentacles. 
Genotype .— Myriozoella ( Myriozoum ) Crustacea Smitt, 1868. Recent. 
ORBITULIPORIDAE, new family. 
The zooecia are regularly arranged vertically; the gemmation is lateral. The 
apertura is terminal. The ovicell is hyperstomial and forms a tube placed in a 
zooecium larger than usual. 
The genera of this family are as follows: 
Orbitulipora Stoliczka, 1861. 
Stichoporina Stoliczka, 1861. 
Batopora Reuss, 1867. 
Mamillopora Smitt, 1872. 
Sphaerophora Haswell, 1880. 
Fedora Jullien, 1882. 
Schizorthosecos Canu and Bassler, 1917. 
f Diplotaxis Reuss, 1867. 
Affinities. —This new family differs from the Conescharellinidae Levinsen, 
1909, in the constant presence of an ovicell. It differs from the Myriozoidae in 
having the ovicell adjacent to a zooecium. 
Historical. —In 1917 w r e included the genera of this new family with the Cone¬ 
scharellinidae Levinsen, 1909, but after a careful study of this latter family based 
upon specimens from the Philippine Islands we believe that the analogy between 
them is purely zoarial and that they must be separated. Their system of incuba¬ 
tion is totally different, indicating that their larval system is also very different. 
In 1885 Koschinsky discovered in the Bavarian Lutetian a series of forms 
which he classed in Stichoporina Stoliczka, 1881. This error has been repeated by 
Waters, Kirkpatrick, Neviani, and Canu. Calvet alone, in 1907, compared Sticho¬ 
porina of authors with Mamillopora Smitt, 1872. In 1919 Waters established the 
truth of this observation by a study of some excellent specimens and classified the 
principal genera as follows: 
A. With a pit: Batopora, Orbitulipora, Sphaerophora, Stichoporina. 
B. Without a pit: Mamillopora, Conescharellina. 
