xiv BRITISH FOSSIL CORALS. 



7. Genus Cyclocyathus. 



Corallum simple, discoidal, and having the same characters as the preceding genus, 

 except that the columella is fasciculate and papillous. 

 Typ. sp., Cyclocyathus Fittonii, nob. 



§ 2. Pali of divers orders, forming two or more coronets. 



8. Genus Trochocyatiius. 



Milne Edw. and J. Haime, loc. cit. x p. 300, 1848. 



Corallum simple, pediculatc or sub-pediculate, but free in the adult state. Calice with 

 a broad but not very deep fossula. Columella well developed, and composed of prismatic or 

 twisted processes disposed fascicularly or in a single row. Pali well developed, entire, free 

 on both edges, and differing in breadth according to the coronet to which they belong. 

 Septa very exsert, broad, thick near the wall, striated laterally, and forming from four to 

 six cycla. Costa often armed. 



Typ. sp., Trochocyatiius mitratus, nob. (T. mitratus et T. plicatus, Milne Edw. and J. Haime, loc. cit., 

 p. 303) ; Turlinolia mitrata, Goldfuss, op. cit., pi. xv, fig. 5 ; Turbinolia plicata, Michelotti, Specim. 

 Zooph. dil., tab. ii, fig. 9. 



9. Genus Leptocyathus. 



Corallum presenting most of the characters of the preceding genus, from which it differs 

 by its subdiscoid form, and its not showing any trace of adherence. 



Typ. sp., Leptocyathus elegans, nob. 



10. Genus Thecocyathus. 



Milne Edw. and J. Haime, loc. cit., p. 317, 1848. 



Corallum simple, very short, and adherent, at least when young. Calice circular, with 

 the fossula shallow. Columella very large, fasciculate, formed by a great number of prismatic 

 processes, and terminated by a flat papillous apex. Pali thick, narrow, short, and entire, 

 those corresponding to the penultimate cyclum of septa the most vieveloped. Septa not 

 exsert, thick, closely set, and almost equally developed ; systems equally developed. Wall 

 covered by a complete epit/ieca, slightly striated transversely, and constituting around the 

 calice a small projecting ring. 



Typ. sp., Thecocyathus tintinnabulum, Milne Edw. and J. Haime, loc. cit., p. 317; Cyathophyllum 

 tintinnabulum, Goldfuss, Petref. Germ., tab. xvi, fig. 6. 



11. Genus Paracyathus. 



Milne Edw. and J. Haime, loc. cit., p. 318, 1848. 



Corallum simple, subturbinate, and having a broad adherent basis. Calice with a large 

 but not very deep fossula. Columella very broad, terminated by a papillous surface, and 



