FROM THE UPPER AND LOWER WHITE CHALK. 5 



The septa are continuous witli what appear to be rudimentary intercostal spaces. 



The laminae are twelve in number ; they project into the circular calice^ but are not 

 exsert. A section proves that they are very stout, even low down in the corallum. 



Length of the corallum, 1 inch. Diameter of the calice, jth inch. 



Locality. Charlton, Kent. In the Collection of the Rev. T. Wiltshii-e, E.G.S. 



This species is mimetic of Parasmilia serpentina, Ed. and H., from the same geological 

 horizon, just as TrocUosmilia cylindrica is mimetic of Parasmilia cylindrica. The Stylo- 

 trocJd of the Cambridge Upper Greensand are closely alhed to this species, which is found 

 in the Grey Chalk and Lower White Chalk. 



Eamilt— ASTR^IDiE. 

 Genus — Trochosmilia. 

 Sub-yenus — Ccelosmilia. 



It is a great question whether Ccelosmilia can stand as a genus. It is impossible to 

 separate its species from those of Trochosmilia by an external examination, and sections 

 prove that there is no columella and a very scanty endotheca. Still there is an endo- 

 theca, and the visceral cavity of the Coral was not open from top to bottom, as in the 

 TarUnolidce. It is true that there is a facies common to the Codosmilice, and that they 

 are a natural group ; but, in fact, they do not differ from a Troclosmilia with scanty 

 endotheca. On studying the genus Trochosmilia it will be noticed that many of its 

 species have never been described with reference to their endotheca. Many were deter- 

 mined from one or two specimens, and sections of the majority have not been made. 

 Now, Trochosmilia sulcata, Ed. and H., has very little endotheca ; it is a species from 

 the Gault, and the Codosmilim are all from the Cretaceous, Eocene, and recent Coral- 

 faunse. In placing Ccelosmilia as a sub-genus, but included in Trochosmilia, it must be 

 admitted that the classification becomes simpler and more natural. Since MM. Milne- 

 Edwards and Jides Haime pubhshed their 'Hist. Nat. des CoraUiaires,' some new 

 species of Ccelosmilia have been published or described. 



The following species have been described : 



1. Ccelosmilia poculmn, Ed. & LI., recent. 



2. „ Faiijasi, „ ^^Hiite Chalk, Ciply. 



punctata, „ ,, 



laxa, „ Norwich Chalk. 



Edwardsi, D'Orb., Sezanne. 



Atlantica, Martin, sp.. Timber Creek, New Jersey. 

 excavata, Hagenow, sp., Chalk of Rugen. 

 radicata, Quenstedt, Nattheim. 



