404 



BULLETIN 106, UNITED STATES NATIONAL MUSEUM. 



Exochclla Jullien, 1888. 

 Didymosetta Canu and Bassler, 1917. 

 Trypematella, new genus. 



They are differentiated from one another in their functions of calcification and 

 their aviciilaria. 



D. Exochella Didymosella r ~- Trypematella 



FIG. 119. Genera of the subfamily Peristomellae Canu and Bassler, 1917. 



A. Bathosella aspera Ulrich, 1901, X20. Lowest Eocene of Maryland. 



B. Romancheina martiali Jullien, 1888, X 20. Recent. 



C. Peristoniella coccinea Abildgaard, 1805. Recent. 



D. Exochella longlrostris Jullien, 1888, X 31. Recent. 



E. Didymosella crassa Canu and Bassler, 1917, X 20. Vicksburgian of Alabama. 



F. Trypematella papulifcra, new species, X 20. Pleistocene of California. 



Genus BATHOSELLA Canu and Bassler, 1917. 



1917. Bathosella CANU and BASSLER, Synopsis of American Early Tertiary 

 Bryozoa, Bulletin 96, United States National Museum, p. 43. 



Cheilostome 



The aperture is oblique without lyrula, cardelles, or rimule. The ovicell is 

 embedded in the distal zooecia. It opens above the aperture and below the frontal 

 mucro in the locella. The frontal is a thick olocyst more or less covered by a 

 pleurocyst,. The zooecia are indistinct. The avicularip, are simple and irregularly 

 placed. The areolae are very rare. No spines. 



Genotype. Bathosella (Mucronella) aspera Ulrich, 1901. 



Range. Upper Cretaceous-Midwayan. 



