12 BRITISH FOSSIL CORALS 



Parasmilia cylindrica and Parasmilia serpentina are readily distinguislied by their 

 external shape ; but, owing to the polymorphic character of Parasmilia centralis, it is 

 by no means easy to separate it from Parasmilia Mantelli and Parasmilia Fittoni. 



Parasmilia Mantelli, Ed. and H., was determined from one specimen alone, and it is 

 clearly united to Parasmilia centralis by Parasmilia Gravesana, Ed. and H., of the White 

 Chalk of Chalons-sur-Marne and Beauvais (Oise). This species has been found in Eng- 

 land. Having found many specimens of Parasmilia centralis with costse like those of 

 P. Mantelli in some parts of the corallum, and found normal costse in others, I consider 

 P. Mantelli a variety of P. Gravesana, and that this last species is a variety and good 

 sub-species of P. centralis. Parasmilia Fittoni, Ed. and H., has a large columella and 

 a definite structural distinction in its tertiary costse from P. centralis. 



The following is a list of the British Parasmilice ; 



1. Parasmilia centralis, Mantel], sp. 





, „ variety Mantelli. 





, „ sub-species Gravesana, Ed. and 11, 



2. 



Fittoni, Ed. and H. 



3. 



, cylindrica, „ 



4. 



, serpentina, „ 



5. 



,, monilis, Duncan. 



6. 



,, granulata, „ 



1. Parasmilia centralis, Mantell, sp. ; sub-species Gravesana, Ed. and IT. PI. VI, 

 figs. 14—17; pi. V, figs. 8, 9. 



MM. Milne-Edwards and Jules Hairae notice that P. Gravesana is "tres voisine de la 

 P. centralis; elle s'en distingue seulement par ses cotes." — 'Hist. Nat. des Coral.,' 

 vol. iii, p. 173. PL V, figs. 10—15. 



In the British Museum. 



2. Parasmilia monilis, Duncan. PI. V, figs. 4 — 7. 



The corallum is long, much curved, and distorted. It is more or less cylindrical 

 above, and contracted here and there. Inferiorly it is pedunculate, the peduncle being 

 small, curved, and long. 



The costa; are nearly equal on the peduncle ; and there they are rather subcristiform, a 

 secondary crest being fomid on each costa. In the intercostal spaces there is either a faint 

 ridge, or a moniliform series of granules. On the body of the Coral the principal cost£e 

 are sharp, wavy, granular, and keeled. They have several smaller and less prominent 



