AKT. 22. 



CYCLOSTOMATOUS BRYOZOA— CANU AND BASSLER. 



91 



apart; the gemmation is peripheral, since the tubes are bifurcated 

 at all heights. The terminal portion is recurved almost at right 

 angles to the zoarial axis; it enlarges much and very rapidly; the 



kM I 





Fig. 20. — Ceriocava coryvibosa Lamouroux, 1821. 



A. Longitudinal section, X 12, illustrating the thin tubes with diaphragms in 

 the central region and the thickened, vesicular walls of the outer portion. 



B, C. Tangential section, X 12 and a portion. X 25, showing the structure. 



D. Transverse section, X 12. 



E. Longitudinal section, X 12, through a branch showing a perpendicular 

 bifurcation. 



Jurassic (Bathonian) : St. Aubin (Calvados), France. 



vesicles of the walls increase in size toward the periphery and leave 

 between them small pores of communication. 



In tangential section the apertures are irregularly polygonal; 

 they are surrounded by a sort of annular canal formed by the section 

 cutting the parietal vesicles. 



