ART. 22. 



CYCLOSTOMATOUS BRYOZOA CANU AND BASSLER. 101 



[Diaeter of apertures 0.22-0.26 mm. 



Measurements. — -^Diameter of ovicell .80 mm. 



[Length of zoarium 15.00 mm. 



Afflmties. — Another specimen in the Canu collection is claviform 

 without an enlarged inferior part; its dimensions are identical and 

 it bears groups of closed zooecia. 



Our species appears to resemble the figure of Radiopora in-flata 

 Simonovitsch, 1871, but Gregory, in 1909, confirms the Radio'pora 

 character of this species, which, however, scarcely appears on the 

 author's figure. 



Occui^^ence. — Cretaceous (Cenomanian) : Essen, Germany. 



Holotype.—C^t. No. 68951, U.S.N.M. 



Genus DITAXIA Hagenow, 1851. 



1851. Ditaxia Hagenow, Die Bryozoen der Maastrichter Kreidebildung, 

 p. 49. 



Leiosoeciidae in which the tubes are short, cylindrical, with tri- 

 parietal gemmation on a thick median lamella. They are recurved 

 at their extremities with irregularly thickened walls. The peristomes 

 are slightly salient in young specimens but absent in the mature stages. 

 The mesopores are little abundant, cylindrical or club-shaped, of 

 variable length. 



Genotype. — Ditaxia anomalopora Goldfuss, 1827. 



Range. — Coniacian — Danian. 



Histoncal. — Hagenow considered the great thickness of the me- 

 dian lamella as the essential character of his genus. Pergens in 1889 

 applied the name to all species provided with club-shaped tubes and 

 with mesopores. Gregory classed the genus in his family Clausidae, 

 characterized by the presence of dactylethrae (or aborted cellules). 

 The accessory cellules being the superior ramifications of the normal 

 tubes are mesopores and not dactylethrae. The diagnosis of 

 Hagenow's genus must therefore be reestablished as above after a 

 study of thin sections of the genotype. It differs from Chilopora 

 'Haime, 1854, in its much larger ovicell in the presence of a very thick 

 median lamella and in the considerable thickening of the extremity of 

 the tubes. 



DITAXIA ANOMALOPORA Goldfuss. 1827. 



Plate 17, figs. »-13. 



1827. Ceriopofu anomalopora Goldfuss, Petrefacta, Germania, vol. 1, p. 33, 



pi. 10, figs, c, d, (not a, J)). 

 1899. Ditaxia anomalopora Gregory, Catalogue of the Cretaceous Bryozoa 



in the British Museum, vol. 1, p. 406; vol, 2, p. 309 (cites bibliography). 



We are not certain that the species figured by D'Orbigny in 1852 is 

 exactly that of Goldfuss, and there is a great confusion in his collec- 



