EARLY TERTIARY CHEILOSTOME BRYOZOA. 9 



SYSTEMATIC DIAGNOSES. 



Order CHEILOSTOMATA Busk. 



Suborder Anasca Levinsen. 



A zooecial hydrostatic system is absent but a zoarial hydrostatic sys- 

 tem is present and is inchided between the cryptocyst and the ectocyst. 



The Anasca are classified under the three divisions Malacostega, 

 Coilostega, and Pseudostega. 



Division I. MALACOSTEGA Levinsen. 



The parietal muscles are attached to the cryptocyst, which is 

 always chitinous. The operculum is a membranous valve. In the 

 fossil forms the frontal wall is quite or partially calcified. 



The families of this division represented in the American Eocene 

 are as follows: 



Electrinidae D'Orbigny, 1851. 



Membraniporae, new group. 



Aeteidae Smitt, 1867. 



Scrupocellariidae Levinsen, 1909. 



Farciminariidae Busk, 1884. 



Eucratiidae Hincks, 1880. 



Family ELECTRINIDAE D'Orbigny, 1851. 



Zooecia having a chitinous frontal. Intertentacular organ present. 

 Larva a cyphonautes. No avicularia. No dietellae. Operculum 

 with thickened border. 



The known genera of the Electrinidae are as follows: 

 Electra Lamouroux, 181G. Eocene-Recent. 

 Memhranipora Blainville, 1834. Recent. 

 Heterooecium Hincks, 1892. Recent. 

 Pyripora D'Orbigny, 1852. Cretaceous-Recent. 

 Herpetopora Lang, 1914. Cretaceous-Vicksburgian. 

 The two latter genera have been placed in the family on account of 

 zooecial resemblance and not from a study of their anatomy. Both 

 of these genera are represented in the Eocene of the United States. 



MEMBKANrPORAE, new group. 



This very large group is too heterogenous to be considered as a 

 single family; indeed it is certain that the genera classified here at 

 present will ultimately be assigned to many families. Unfortunately 

 we are ignorant of the larvae and researches upon the anatomy of 

 these forms have not been made. 



The material upon which our present researches are founded is 

 most abundant; but as it is impossible to establish a satisfactory 



