EARLY TEETIARY CHEILOSTOME BRYOZOA. 33 



times a single broad) supporting teeth. The subopercular area of 

 the avicularia has an unusually strongly developed, sometimes almost 

 complete, cryptocyst. The ovicells are endotoiehal. (After Levin- 

 sen, 1909.) 



Genus CELLARIA Authors. 



The zoarium is articulated, with cylindrical segments (inter- 

 nodes). The ovicell is endotoiehal and is closed by a peculiar, chi- 

 tinous operculum moved by special muscles. The operculum is 

 formed of a chitinized inner part, closing the aperture, covered by 

 the exterior ectocyst. 



Genotype. — Cellaria jistulosa Linnaeus, 1768. 



Range. — Jacksonian-Recent. 



Several well-marked new species occur in the American Eocene. 



Family COSCINOPLEURIDAE Canu, 1913. 



The apertura is semilunar, marginated, anterior, never terminal. 

 The ovicell is hyperstomial, embedded in the distal zooecia, never 

 closed by the operculum. The onychocellaria are straight but typical. 

 The known genera are: 



Coscinopleura Marsson, 1887. 

 Escharipova D'Orbigny, 1851. 

 Macropora MacGillivray, 1893. 

 ? Quadricellaria D'Orbigny, 1850. 



Genus COSCINOPLEURA Marsson, 1887. 



1887. Coscinopleura Marsson, Die Bryozoen der Schreibkreide der Insel 

 Riigen, Paleontologische Abhandlungen, vol. 4, p. 71. 



The margins of the zoarium are bordered by large vibracula. The 

 frontal is deprived of pores and avicularia. 



Genotype. — Coscinopleura {Eschara) elegans Hagenow, 1840. 

 Range. — Cenomanian-Thanetian. 



Eschara digitata Morton, 1834:, so prolific in the upper Cretaceons 

 (Vincentown marl) of New Jersey and Delaware is a typical species 

 of this genus. 



Genus MACROPORA MacGillivray, 1895. 

 1895. Macropora MacGillivray, Monograph Tertiary Polyzoa Victoria, 

 Transactions Royal Society Victoria, vol. 4, p. 54. 



In 1909 Levinsen described this genus as follows : 

 The zocecia very thick-walled, provided with pores but without 

 spines and without opesiules. The zocecial aperture is provided with 

 a well-developed vestibular arch. Ovicells and avicularia wanting, 

 but among the zocecia we find some which have an aperture of a 

 different form and whose distal margin is furnished with three 

 membranous feeler-like filaments. Dietellae. 

 52091°— 17 3 



