214 OX YCHOCELL A . 



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. tuber osa, Novak, 1 agrees in 

 its general characters, but it possesses numerous vibracularia and 

 is more ornamented. Marsson's figure 2 of M. lyra (Hag.) shows 

 that this Maestricht species belongs to the same group, but it may 

 be easily distinguished from M. jurassica by its oval aperture. 



Family MICROPOEID^E. 



Diagnosis. Athyriata with a calcified front wall. Zocecia sur- 

 rounded by raised margins. No internal diaphragms. Ooacia 

 external. 



ONYCHOCEKLA, Jullien, 1881. 



Diagnosis. Microporidae with large, vicarious avicularia scat- 

 tered over the zoarium. 



Onychocella flabelliformis (Lamouroux), 1821. 



SYNONYMY : 

 Flustra flabelliformis, Lamouroux, 1821, Expos. Meth. p. 113, footnote, pi. Ixxvi. 



figs. 11-13. 



Eschara Bronn, 1848, Nomencl. p. 470. 



,, ,, Bronn, 1849, Enum. p. 134. 



D'Orbigny, 1852, Pal. franq. Terr. cret. t. T. p. 343. 



non Pictet, 1857, Traite Pal. ed. 2, t. iv. p. 98, pi. xc. fig. 5. 



Onychocella bathonica, Gregory, 1894, Jur. Cheil. : Geol. Mag. dec. 4, vol. ii. 

 p. 63, 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 



1 Novak. Beitrag zur Kenntniss der Bryozoen der bohmischen Kreideforma- 

 tion: Denk. k. Akad. Wiss. Wien. Bd. xxxvii. Abth. 2, 1877, p. 92, pi. i. 

 figs. 1-3. 



2 Th. Marsson. Die Bryozoen der weissen Schreibkreide der Insel Riigen. Pal. 

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



