14 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 01. 



tical, transverse, reflected oeciostome. It results from the develop- 

 ment of the peristomie of a tube belonging to a verticell. The species 

 is therefore a Mecynoecia. 



Waters long ago expressed his doubts about the reality of the genus 

 Sjyiropora Lamouroux, 1821. The discovery of the ovicell confirms 

 his opinion, since the genus Mecynoecia contains a number of species 

 with the zoarial form of both Entalophora and Spiropora. Never- 

 theless as this species and two or three others show in transverse sec- 

 tion a spiral arrangement of the tubes, it is possible that Lamouroux's 

 genus may still be retained. 



Occurrence. — Cretaceous (Coniacian) : Villedieu (Loir-et-Cher) . 

 France, and many other localities and horizons. 



PUsiotypes.—C?it. No. 68905, U.S.N.M. 



MECYNOECIA RAMOSISSIUA D'Orbigny. 1851. 



Plate 1, figs. 12, 13. 



1845. Pustulopora echinata Micheun (not Roemer), Iconographie zoophyto- 



logique, p. 211, pi. 53, fig. 5. 

 1851. Entalophora vendinnensis d'Orbigny, Paleontologic fraugaise. Ter- 

 rain Cr^tace, p. 871, pi. 617, figs. 15-17. 

 1851. Entalophora ramoaissima d'Obbigny, Paleontologie frangaise, Ter- 

 rain Crgtace, pi. 619, figs. 6-9. 

 1851. Laterotubiyera ccnomana d'Orbigny, Paleontologie fraugaise. Ter- 

 rain Cretace, p. 785, pi. 618, figs. 1-5. 

 1899. Entalophora vendinnensis Gbegoby, Catalogue of the Cretaceous 

 Bryozoa in the British Museum, vol. 1, p. 241 (not Canu 1897- 

 Mecynoecia stipata, new species). 

 1899. Entalophora rni)iosissima Gkkgory, Catalogue of the Cretaceous 

 Bryozoa in the British Musenm, voL 1, p. 244. 



Diameter of peristome 0.14-0.18 mm. 



Zooecial width .24mm. 



Distance between orifices .30 - .50 mm. 



Separation of orifices .60 mm. 



Variations. — Gregory has reported this species under three dis- 

 tinct names, the material in the British Museum appearing insuf- 

 ficient to determine the variations. In 1889 Pergens had not united 

 Entalophora vendinnensis with Entalophora raniosissima, for he 

 still gave more importance to the exterior aspect. In 1897, Canu, 

 deceived by the aspect of a related species, maintained the same dif- 

 ferences, but his Entalophora vendinnensis is a different species (see 

 M. stipata) on account of its different measurements and ovicell. 



In comparing numerous specimens in the Canu collection it is 

 not possible to maintain the former distinctions; there is but a single 

 species with varied aspects in which however the ovicell is the same. 

 It is not rare to find on a single specimen the two forms Entalophora 

 with the tubes in quincunx and Laterotubigera having tubes in 

 transverse verticells. 



Measuremen ts .■ 



