Dr. J. W. Gregory — Some Jurassic Bryozoa. 63 



but sometimes there is only one. The aperture is oval. They are 

 medium in size. 



Dimensions : Length of a zooecium 1"3 mm ; breadth 0*85 mm. 



Distribution : Calcaire a polypiers. (Bathonian.) Ranville, Nor- 

 mandy, France. 



Type : Brit. Mus. D 180. 



Affinities of the Species. — This species belongs to a group 

 which is well represented in the Cretaceous, and it is advisable to 

 compare it with the following seven species. From Memhranipora 

 bipunctata, Goldf.,^ it differs in that in the latter the aperture is oval, 

 the zooecia are less regular, and there is but one avicularium ; the 

 species are allied in general aspect and the structure of the rim. 

 M. velamen, Groldf.,^ resembles the new species in the shape of the 

 aperture, but it has a more extensive front wall, larger (and possibly 

 vicarious) avicularia, and the shape of the zooecia is diiferent. If. 

 cypris, D'Orb.,^ agrees in the shape of the zooecia and the character 

 of the rim, but has an oval aperture and no avicularia. M. regularis, 

 D.Orb., agrees in the structure of the avicularia, but the other 

 characters show that the species are clearly different. M. tuberosa, 

 Novak, ^ agrees in its general characters, but it possesses numerous 

 vibracularia and is more ornamented. Marsson's figure^ of J/. Jyra, 

 Hag., shows that this Maestricht species belongs to the same group, 

 but it may be easily distinguished from If. jurassica by its oval 

 aperture. 



Family : Microporid^. 



Genus: Onychocella, Jullien, 1881. 



Species : Onychocella bathonica, n. sp. (Fig. 2). 



Diagnosis. 



Zoarium : Encrusting ; an extensive thick crust. 



Zooecia : Skittle-shaped, the lower part being like half a hexagon, 

 closed above by a well-rounded arc. Aperture ovato-deltoid with a 

 blunt upper end ; the lower margin is entire and but slightly curved 

 and has a somewhat raised thin margin ; the aperture is large. 

 Front wall small, triangular, depressed ; minutely granular. Raised 

 rim, plain, non-crenulate. 



Avicularia : Large, vicarious ; long, tapering at each end ; irre- 

 gularly scattered over the zooecium. Apertures obovate. A small, 

 triangular front wall both above and below the aperture. 



Dimensions : Length of a zooecium ; 1 mm. ; breadth, 0-8 mm. 



1 Cellepora bipunctata, Goldfuss, Pet. Germ. Bd. I. Ht. 1, 1827, p. 27, pi. ix. 

 fig. 7, and Hagenow, Die Bryozoen der Maastrichter Kreidebildung, 1851, p. 76, 

 pi. ix. fig. 9. 



^ CeUepora velamen, Goldfuss, op. cit. p. 26, pi. ix. fig. 4, and Hageno-ff, op. cii. 

 p. 97, pi. xii. fig. 1, in which the type is refigured. 



3 Pal. Franc. Terr. Cret. t. v. p. 551, pi. 607, figs. 11-12. 



Flustrma regularis, D'Orb., ibid. p. .306, pi. 702, figs. 17-19. Flustrina elegans, 

 p. 302, pi. 701, figs. 17-19, appears to be only a worn variety of this species. 



* Novak, Beitrag zur Kenntniss der Bryozoen der bohmischen Kreideforraation 

 Dank. k. Akad. Wiss. Wien. Bd. xxxvii. Abth. II. 1877, p. 92, pi. i. figs. 1-3. 



5 Th. Mwrsson, Die Bryozoen der weissen Schreibkreid der Insel Eiigen. Pal. 

 Abth. Bd. IV. Ht. 1. 1887, p. 59, pi. v. fig. 17. 



