CYCLOSTOMATOUS BRYOZOA CANU AND BASSLER 



91 



fied and could not be sectioned, but a well-preserved example from 

 Berklingen has afforded some interesting results. In the transverse 

 section here figured the tubes are polygonal, with a rounded center, 

 cylinth'ical, of uniform diameter. The recurved parts of the tubes 

 and the mesopores have very thick vesicular walls in confirmation of 

 Gregory's figure 61. Gemmation takes place especially in the vicin- 

 ity of the central axis. 



The tangential section shows small scattered mesopores embcckled 

 in the zoarial epitheca. 



Occurrence. — Lower Cretaceous: Sainte-Croix, Switzerland (Valan- 

 gian) ; Berklingen, Germany. 



Plesiotypes.—Ciii. No. 69946, U.S.N.M. 



Genus SPARSICAVEA D'Orbigny ,1853 



SPARSICAVEA IRREGULARIS D'Orbigny. 1853 



Plate 15, figs. 11-14. 

 1853. Sparsicavea irregularis D'Ohbigny, Paleontologie fran- 

 ^aise, Terrain Cr6tac6, vol. 5, p. 949, pi. 617, figs. 

 5-7. 



Measurements. — Diameter of aperture 0.07-0.08 

 mm.; diameter of peristome, 0.12 mm.; diameter of 

 zoarium, 1-2 mm. 



Structure. — Our determination is exact, as our 

 specimens are rigorously analogous to those of 

 D'Orbigny. His figure is not altogether exact, as 

 admitted by himself, the unequal spacing of the 

 peristomes not being visible. Our photographs 

 show this feature very well. Mesopores are rather 

 numerous; they are infundibuliform at their ex- 

 tremity and appear consequently smaller in tangen- 

 tial section. The peristome is salient and thick. 



The longitudinal section shows the usual feature 

 of Sparsicavea, namely club-shaped tubes, peripheral 

 and axial gemmation, parietal mesopores (=macu- 

 lae of Gregory) , with very thick walls. In transverse 

 section the thickening of the walls of the mesopores 

 forms a regular epithecal zone. 



All the known ovicelled species with Sparsicavea characters are 

 referred to the genus Parascosoecia, but until the ovicell of the 

 present one is known we believe it best to refer it to the older name. 



Occurrence. — Lower Cretaceous (Aptian) : Faringdon, England; 

 Machoremenil (Ardennes), France. 



Plesiotypes.— Cat. No. 69947, U.S.N.M. 



Fig. 45.— Sparsicavea 

 irregularis D'Orbig- 

 ny, 1851. A. Trans- 

 verso section, X 16. 

 B. Lon gitudinal 

 section, X 10. Low- 

 er Cretaceous (Ap- 

 tian): Faringdon, 

 England 



