34 PROCEEDINGS OP THE NATIONAL, MUSEUM vol.67 



Genus NEUROPORELLA Hennig, 1894 



1894. Neuroporella Hennig, Studies ofver Bryozoerna; Sveriges Kritsystem. 

 II Cyclostomata Lunds Universitets Arsskrift, vol. 30, No. 8, p. 26. 



The zoarium is formed of irregular incrusting, iini or miilti lamellar 

 masses. The centers of convergence of the veiniiles form smooth 

 salient points. The internal structure is identical with that of 

 Neuropora. 



Genotype. — Neuroporella ignahergensis Hennig, 1894. Cretaceous. 

 This genus is only a zoarial form of Neuropora, but we maintain it 

 provisionally in order to facilitate determination and because our 

 sections are not numerous enough for a more detailed study. 



NEUROPORELLA HEMISPHERICA, new species 



Plate 26, figs. 1-5; Plate 31, figs. 5, 6 



Description. — The zoarium is massive, hemispherical, with a con- 

 cave and somewhat narrower base; it is formed of many superposed 

 lamellae. The orifices are polygonal, separated by small salient 

 tubercules. The veinules are broad, sailient, smooth, and bifurcated. 



Measurements. — Diameter of orifice, 0.12-0.16 mm.; diameter of 

 large zoarium, 17 mm. 



Affinities. — This species differs from Neuroporella ignahergensis 

 Hennig 1894, in the absence of centers of convergence of the very 

 salient veinules and in its much larger orifices. 



In longitudinal sections the tubes are cylindrical with peripheral 

 gemmation, traversed by numerous diaphragms. A large number of 

 the diaphragms are formed simultaneously and form the zonal lines. 



In tangential sections the tubes are polygonal and their walls are 

 very thick and opaque. 



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

 (rare) . 



Coty pes. —C&t. No. 69879, U.vS.N.M. 



Genus SPINOPORA Blainville, 1830 



The zoarial surface bears very salient, smooth tuberosities, but 

 veinules are not present. The tubes have internal spines. The 

 orifices and the internal structure are identical with Neuropora. 



Genotype. — Spinopora (Ceriopora) mitra Goldfuss, 1827. Creta- 

 ceous. The large tuberosities correspond to the solidified tubes like 

 the centers of convergence in Neuropora. This genus appears to us, 

 therefore, as a Neuroporella without veinules. The genotype from 

 the Campanian of Sweden and the Island of Riigen is the only species 

 heretofore known. 



