36 



PROCEEDINGS OF THE NATIONAL MUSEUM 



ill 1920. The transverse section especially is puzzling and we can 

 not explain its structure because the tubes in it are not rounded. 

 This structure is peculiar to this group, and it is little probable that 

 all the species which we have cited as belonging to this genus, 

 because of the nature of the ovicell, have an identical structure. 



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

 Switzerland, and Censea (Doubs), France. 



Plesiotype.— Cat. No. 69881, U.S.N.M. 



MECYNOECIA (SPIROPORA) VERTICILLATA 

 Goldfuss, 1827 



1850. Spiropora neocomiensis D'Orbigny, 

 Paleoiitologie frangaise, Terrain 

 Cretace, vol. 5, p. 708, pi. 742, 

 figs. 1, 2. 



1865. Spiropora verticillata Beis.sel, Ue'jer 

 d i e Bryozoen der Aachen er 

 Kreidebildung, Naturku n d i g e 

 Verhandelingen Hollandsche 

 Maatschappij der Weltenschap- 

 pen te Haarlem, ser. 2, vol. 22, p. 

 70, pi. 8, figs. 91-93. 



1869. Spiropora neocomiensis De Loriol, 

 Monographle de I'etage Urgouien 

 de Landeron, Memoires de la 

 Society helvetique des Sciences 

 naturelles, vol. 23, p. 37, pi. 2, 

 fig. 18. 



1909. Spiropora verticillata Gkegory, 

 Catalogue of the Cretace ous 

 Bryozoa in the British Museum, 

 vol. 1, p. 256, pi. 11, fig. 5. (Bi!)- 

 liography and geological distri- 

 bution.) 



1922. Mecynoecia ? verticillata Canu and 

 Bassler, Studies on the Cyclo- 

 stomatous Bryozoa, Proc. U. S. 

 National Museum, vol. 61, p. 13, 

 pi. 1, figs. 16, 17. 



Fig. 17— Mecynoecia icaunevsis D'Orbigny, 1850. MeaSVrementS.- — Diamctcr of pcri- 



A-B. Transverse and longitudinal sections, n OA ]' i -f 



X16. Lower Cretaceous (Valangian): Saiute- StOHie, L).ZU-U.24 mm.; CUSiance 01 



: Croix, Switzerland vcrticells, 0.60-0.90 mm. The 



measurements are identical with specimens from the French Conia- 

 bian. In longitudinal section the tubes are cylindrical, with regular 

 peripheral gemmation. 



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

 zerland, etc. 



