CYCLOSTOMATOUS BRYOZOA CANU AND BASSLER 



69 



The longitudinal section of the extremity of a young branch 

 shows the disappearance of the central bundles of tubes, the latter 

 expanding in fan-shape around the zoarial axis. A longitudinal 

 section made through a branch with facettes was not very success- 

 ful, as silicification had invaded the tubes of the exterior lamella. 

 The peristomes were arranged in quincunx and the tube appeared 

 with thickened walls without any of them having been sectioned 

 tangentially. In transverse section the central bundle is quite 

 apparent. 



Fig. 35. — Ceriocava multilamellosa, new species. A. Transverse section of specimen D, X IG. B. Trans- 

 verse section, X 16. C. Section through a branch, X 16, in which the exterior lamella is engendering 

 an adventitious branch. D. Longitudinal section (see also A), X 16, in which the orifices are arranged 

 in quincunx. E. Longitudinal section, X 16, at the extremity of a branch. F. Longitudinal section, 

 X 16, through a multilamellar branch. Lower Cretaceous (Valangian): Sainte-Croix, Switzerland 



We have had the fortune to find a branch containing these sup- 

 posed lamellae with their zone of growth. The longitudinal section 

 of this branch shows that the tubes are arranged in a different direc- 

 tion from that of the interior lamella; their extremity is alone visi- 

 ble and they appear there shorter than they are in reality. The 

 study of the transverse section confirms this arrangement. 



