BRITISH FOSSIL CORALS. 



Family ASTREID^E (p. xxiii). 

 Tribe ASTREINJE (p xxxi). 



Genus Cryptangia (p, xliv). 

 1. Cryptangia Woodii. Tab. I, figs. 4, 4 a, 4 b, 4 c, 4>d, 4<e. 



Cladocora cariosa, Lonsdale; in Searles Wood's Catal. Ann. of Nat. Hist., vol. xiii, 



p. xii, 1844. 1 

 Cryptangia Woodii, Milne Edwards and J. Haime, Mem. sur les Astreides, Comptes rend. 



de l'Acad. des Sciences, vol. xxvii, p. 496, 1848. 



This singular fossil Coral is always found immersed in a mass of Cellepora, a peculiarity 

 which is also met with in another species of the same genus, belonging to the Faluns of 

 Touraine. At first sight, the vesicular mass formed by these Bryzoa may easily be mistaken 

 for a cellular epithecal ccenenchyma, resembling that of Sarcinula ; but an attentive examina- 

 tion of the cells will lead to a recognition of their real nature, and similar masses of Cellepora, 

 not containing any Cryptangia, are often found in the same localities. It is however 

 remarkable, that Corals of this genus should never be found adhering to other extraneous 

 bodies, and should always take up their abode on a cluster of Cellepora, which, increasing 

 as they themselves grow up, imbeds them so completely, that the calices alone remain 

 free on the surface of the common mass. 



The mode of multiplication of Cryptangia is also worthy of notice. These Corals 

 always form clusters, and must be produced by gemmiferous stolons, but the radiciform 

 expansions from which they must proceed do not become sclerenchymatous, and leave 

 little or no trace of their existence ; so that when the soft parts are destroyed, as is always 

 the case in fossils, the different corallites appear to be quite independent, and would be 

 free, were it not for the extraneous cellular mass in which they are so deeply immersed. 

 It is therefore easy to perceive that these Corals differ widely from Cladocora, to which 

 they were referred by Mr. Lonsdale, and are equally distinct from the generic forms to 

 which the name of Lithodendron, applied by M. Michelin to the Touraine species, had 

 been previously given. They are nearly allied to the Astreina reptantes, for which we have 

 established the genera Angia and Bhizangia, *mt must constitute a separate generic group, 

 which we have proposed calling Cryptangia. 



1 The Madrepora cariosa of Goldfuss, to which this fossil was referred by the above-mentioned author, 

 is a true Madrepora, and neither the oue nor the other can be placed in Ehrenberg's genus Cladocora, 

 The typic specimen of M. cariosa, figured and described by Goldfuss, is preserved in the Museum of Bonn, 

 where it was attentively examined by one of us ; it is a fossil of the Parisian basin, having a spongy 

 ccenenchyma, and the visceral cavity of the corallites divided into two parts in consequence of the great 

 development of two opposite primary septa. 



