128 PROCEEDINGS OF THE NATIONAL MUSEUM, vol.61. 



Sections of this species are difficult to make on account of the 

 irregularity of its branches. We illustrate the best of our sections ; 

 and although they are not perfect, the real structure is shown. 



The tubes are cylindrical, short, with triparietal gemmation, with- 

 out peristome; their extremity is quite thick, forming a calcareous 

 dilation perforated by a vacuole. The dorsal is ven^ thick, of lamel- 

 lar structure, and perforated by vacuoles. 



The ovicell was long ago illustrated by Hagenow, but unfortu- 

 nately has not been found again. We are therefore ignorant as to 

 whether his figure is entirely exact. His drawing is too small and 

 the tubes are not visible. Nevertheless, the place of the ovicell, its 

 form, and the similarity of the sections cause us to place this species 

 in Polyascosoecia. 



The section given by Gregory is a meridian section ; it confirms us 

 in the nature of the adventitious pores, which are clearly vacuoles. 



Geological distribution. — Cretaceous (Campanian) : Riigen, Ger- 

 many. 



Cretaceous (Maastrichtian) : Maastricht, Falkenberg, and Petit 

 Lanage (Limbourg), Holland. 



Pledotypes. —C?invi collection and Cat. No. 68970, U.S.N.M. 



POLYASCOSOECIA CANCELLATA Goldfuss, 1829. 



1829. Retepora cancellata Goldfuss, Petrefacta Germaniae, vol. 1, p. 103, 



pi. 36, fig. 17. 

 1851. Idmonea cancellata Hagenow, Bryozoen der Maastriehter Kreide- 



bildung, p. 29, pi. 2. fig. 7. 

 1SG9. Retecava concellata Gregoby, Catalogue of the fossil Bryozoa in the 



British Museum. Cretaceous, vol. 1, p. 202 (Bibliography). 

 1894. Idmonea cancellata Hennig, Stndien ofver Bryozoerna I Sveriges 



Kritsystem, II, Lunds Universitets Arssdrift, vol. 30, no. 8, p. 10, 



pi. 1, figs. 4-6. 



Structure. — Thin sections are very difficult to interpret in species 

 with a thick lamellar structure. Nevertheless by combining all the 

 different sections we can comprehend the real structure of the present 

 species. 



In longitudinal section the tubes are cylindrical with triparietal 

 gemmation. A very thick lamellar tissue entirely surrounds the 

 zoarium; it is perforated by the vacuoles. This structure is abso- 

 lutely identical with that of Polyascosoecia lichenoides Goldfuss, 

 1829, and of P. coronopus, the genotype. Although we have not dis- 

 covered its ovicell, we do not hesitate to class this species in the genus 

 Polyascosoecia. 



Geologic distribution. — Cretaceous (Campanian) ; Riigen, Ger- 

 many (Hagenow, Marsson). 



Cretaceous (Maastrichtian) ; Maastricht, Petit-Lanage, Fauque- 

 mont (Limbourg), Holland (Hagenow), Royan (Charente- 

 inferieure), France (D'Orbigny). 



