THEONOA. 183 



form with broadened ridges I feel bound to separate as a distinct 

 species, and it may well be named after the author who first 

 described it, T. michelini. 



SPECIMEN. 



D. 2186. Inferior Oolite. Near Leckhampton. Brodie Coll. Figd. PL X. 

 Fig. 2. 



4. Theonoa michelini, n.sp. 



SYNONYMY : 

 Theonoa distorta (non Lamx.), Michelin, 1846, Icon. Zooph. p. 232, pi. Iv. 



fig- 7. 



,, ,, (non Lamx.), Haime, 1854, Bry. jurass. : Mem. Soc. geol. 



France, ser. 2, t. v. p. 205, pi. x. fig. 2. 



Diagnosis. Zoarium massive ; roughly cylindrical. The zocecia 

 open on the upper surface, in great groups, which occupy a broad 

 expanse of the surface. 



Distribution. Bathonian : Langrune, near Caen. 



Affinities. This species is accepted on the authority of the 

 figures of Michelin and Haime. It differs from Th. distorta, 

 Lamx., by occurring in cylindrical masses instead of being en- 

 crusting, and by having the apertures in broad sheets instead of 

 narrow ridges. It differs from T. clathrata, to which it is more 

 nearly allied, by the form of the zoarium, and by having the 

 depressions between the apertures as a few broad areas instead of 

 many small, disconnected, round patches. 



INDETERMINABLE SPECIES. 



Theonoa ? sulcata, Ferry. 



Theonoa sulcata, Ferry, 1862, Bajoc. Ma9on, pt. i. : Mem. Soc. linn. Norm. 



t. xii. p. 14. 

 ,, ,, "Waagen, 1868, Zone ^.mm. sowerbyi: Geogn. Pal. Beitr. 



Bd. i. Ht. 3, p. 643, pi. xxxii. fig. 11. 



Distribution. Bajocian : Place, Saone-et-Loire. 



Affinities. Ferry's description suggests the possibility of this 

 form being an Actinopora, but Waagen remarks that it may be the 

 same as his Theonoa (Apsendesia?) parvecristata. 



