AKT. 2] CYCLOSTOMATOUS BRYOZOA CANU AND BASSLEK 57 



In transverse section the tubes are equally rounded, with thick 

 walls. In longitudinal sections they are cylindrical, with peripheral 

 gemmation oriented around an imaginary axis. The dorsal tubes 

 are closed (intrazoarial gemmation) . The zooecial walls are vesic- 

 ular, with very small elements. This is very much like the section 

 in Frondipora, but the ovicell is altogether different. 



Occurrence. — ^Lower Cretaceous (Valangian) : Sainte-Croix (Vaud), 

 Switzerland. 



Plesioty pes. —Cat. No. 69905, U.S.N.M. 



Family THEONOIDAE Busk 



The family Theonoidae, as defined by Gregory in 1899 and 1909, 

 embraced the following genera : 



Actinopora D'Orbigny, 1853, Conotuhigera D'Orbigny, 1853 {Serie- 

 tuhigera D'Orhigny, 1853), Multitubigera D'Orbigny, 1853, Theonoa 

 Lamouroux, 1821, and Retenoa Gregory, 1909, with Multifascigera 

 D'Orbigny, 1853 (= Meandrocavea) , Lopholepis Hagenow, 1851, and 

 Radiofascigera D'Orbigny, 1853, probably belonging to the Osculi- 

 poridae. In its ovicell Retenoa is a typical member of the Cytisidae. 

 Radiofascigera in its ovicell, classed with doubt in the Osculiporidae, 

 ought to be maintained in the vicinity of Actinopora (multiserial) and 

 of Multitubigera. 



The known ovicells are close to those of the Cytisidae without 

 being perfectly identical. The family of Theonoidae could be main- 

 tained therefore with some restrictions. Unfortunately, the ovicell 

 of the type genus Theonoa is still unknown. On the other hand, the 

 uniserial Actinopora of the complanata group {^ organisans) have a 

 different ovicell of the type of Plagioecia. 



If the family should be maintained it ought to contain the following 

 genera : 



Actinopora (multiserial) D'Orbigny, 1853, Radiofascigera D'Orbigny, 

 1853, Multitubigera D'Orbigny, 1853, and probably according to 

 zoarial resemblances Multifascigera D'Orbigny, 1853, Lopholepis 

 Hagenow, 1851, Theonoa Lamouroux, 1821, and Serietubigera 

 D'Orbigny, 1853. 



Although established on simple zoarial appearances, all of these 

 genera, after a study of the known sections, appear to have an evi- 

 dent reality, the mode of gemmation and the arrangement of the 

 tubes serving as generic characters. 



Genus ACTINOPORA D'Orbigny, 1853 



ACTINOPORA STELLATA Koch and Dunker. 1837 



Plate 6, figs. 1, 2 



1909. Actinopora stellata Gregory, Catalogue of the Cretaceous Bryozoa, vol. 2, 

 p. 21. (Bibliography.) {Actinopora regularis D'Orbigny, 1853.) 



