432 



BULLETIN 106. UNITED STATES NATIONAL MUSEUM. 



cell opening into the peristomie. In the Smittinidae the peristomie is formed by 

 the development of a peristome with spines; in the Stomachetosellidae it is formed 

 by the thickening of the frontal. 



We have founded our generic classification on the aspect of the ovicell and on 

 the variations of the escape of the larvae, an important function. All the other 



A. Stomachetosella B. Enoplostomella 



C. Metradolmm 



D. Schizemiella E. Leiosella F. Metrocrypta G. Ochetosella 



FIG. 129. Genera of Stomachetosellidae Canu and Bassler, 1937. 



A. Stomachetosella crussicollis Canu and Bassler, 1917, X 20. Vicksburgian of Alabama. 



B. Enoplostomella defixa Canu and Bassler, 1917, X 20. Vicksburgian of Alabama. 



C. Metradolmm obliqiium, new species, X 20. Jacksonian of North Carolina. 



D. Schizcmirlla clnibornirn Canu and Bassler, 1917, X 20. Claibornian of Alabama. 



E. Leiosella rostrifera Canu and Bassler, 1917, X 20. Vicksburgian of Alabama. 



F. Metrocri/iita bi//'i'iilcul/i Canu and Bassler, 1917, X 20. Middle Jacksonian of North 

 Carolina. 



G. Ochetosella jacksonica Canu and Bassler, 1917, X 20. Middle Jacksonian of North 

 Carolina. 



functions, reproduction, hydrostatic, calcification, and passage of the eggs, remain 

 exactly the same. 



Genus STOMACHETOSELLA Canu and Bassler, 1917. 



1917. Stomachetosella CANU and BASSLER. Synopsis American Early Tertiary Cheilo- 

 stonie Bryozoa, Bulletin 96, United States National Museum, p. 45. 



The ovicell entirely surrounds the apertura. The frontal is a tremocyst with 

 wide-mouthed tubules. No avicularia. The peristomice of the ovicelled zooecia 

 possesses a straighter rimule-spiramen. 



Genotype. ^fninnr/ii-fosrfJti crassicollis Canu and Bassler, 1917. Vicksburgian. 



