180 THEONOA. 



Theonoa clathrata, Friren, 1893, Bry. ool. inf. Metz : Butt. Soc. Hist. nat. 



Metz, ser. 2, t. vi. p. 55. 



,, Gregory, 1896, Rev. pt. vi. : Ann. Mag. Nat. Hist. ser. 6, 



vol. xvii. p. 290. 



Diagnosis. Zoarium dense, massive ; roughly spherical. The 

 surface of the zoarium is broken into ridges, which are short, 

 broad, and blunt. They never rise into high, bilaminate sheets. 

 Four or five apertures occur together, in one width of a ridge. 



DISTRIBUTION. 



ENGLAND : 



Great Oolite: Bath (fide Morris). 

 FOREIGN : 



Bathonian : Ranville ; Lebisey ; Caen ; Oustreham and St. Aubin 



(fide Michelin). 



Bajocian : Plappeville-les-Metz and Montvaux ; Flace, near Ma^on, 

 Haut-Saone. 



?. This is the best known species of the genus, of 

 which it is the type. It reminds one, by its low, blunt ridges, 

 and the structure of the zoarium, of Alveolaria semiovata, Busk, 

 of the Crag ; but the ridges do not unite into such sharply angular 

 closed figures, and have no well-marked central lamina. 



LIST OF SPECIMENS. 



B. 4561. Bathonian Calcaire a polypiers. Ranville. Tesson Coll. 

 60237. ,, , , 



2. Theonoa bowerbanki, Haime. 



SYNONYMY : 

 Theonoa bowerbanki, Haime, 1854, Bry. jurass.: Mem. Soc. gtol. France, ser. 2, 



t. v. p. 205, pi. x. fig. 3. 

 Pictet, 1857, Traite Pal. ed. 2, t. iv. p. 130. 

 ,, Wright, 1860, Subdiv. Inf. Ool. : Quart. Journ. Geol. 



Soc. vol. xvi. p. 12. 

 Witchell, 1882, Geol. Stroud, p. 48. 

 ,, Vine, 1883, 3rd Rep. Foss. Polyz. : Rep. Brit. Assoc. 



1882, p. 265. 



Woods, 1891, Cat. Type Foss. Woodw. Mus. p. 49. 



,, ,, Friren, 1893, Bry. ool. inf. Metz: Bull. Soc. Hist. nat. 



Metz, ser. 2, t. vi. p. 56. 



,, ,, Gregory, 1896, Rev. pt. vi. : Ann. Mag. Nat. Hist. ser. 6, 



vol. xvii. p. 290. 



