62 BRITISH FOSSIL CORALS. 
C. cylindrica, C. Breda, and C. Koninckii, have only six large pali, whereas in C. Bowerbankit 
the number of these organs amounts to twelve. C. devigata' differs from the above- 
described species, by the pali being narrow, and very thick, and C. Debeyana by the 
existence of a well-marked epithecal band near the calice. 
M. Aleide d’Orbigny has, in a recent publication,’ referred to this species as the type 
of his new genus Amdblocyathus, which he defines as being Cyathina, with a circular calice 
and a round columella. He adds that’ Amblocyathus is a lost genus, and contains three 
fossil species belonging to the Neocomian and Albian’ strata. We must, however, beg 
leave to remark, that the two above-mentioned characters are met with in almost every 
species of our Cyathina, and most especially in C. eyathus, which is the type of the genus 
Cyathina, and is actually living in the Mediterranean sea. Only two of the species 
referred to the genus Cyathina in our ‘Monograph of the Turbinolide’ present a slightly 
oval calice and a transversal columella—C. pseudoturbinolia and C. Guadulpensis. In 
C. Smithii the columella is oblong, but the calice is circular, or nearly so. If it be con. 
sidered necessary to separate the Cyathina with a circular calice from those that have an 
oval calice, it would therefore be more proper to give a new generic name to the latter, and 
not to change the denomination of the group containig the very species for which 
Ehrenberg first established the genus Cyathina. But this innovation, proposed by 
M. d’Orbigny, appears to us as beg im every respect unnecessary, for the shght deformation 
of the calice and the columella which forms the sole basis of the new generic division, can 
hardly be considered as characters of sufficient value; species that differ in no other 
respect are often found to vary in this way, and even specimens belonging to the same 
species sometimes differ much in the form of the calicular margin. ‘Thus, although the 
calice is circular, or nearly so, in most specimens of C. cyathus and C. Smithii that are met 
with, we have seen some that were compressed, and had the calice as oval as in C. pseudo- 
turbinolia and C. Guadulpensis ; similar deviations from the normal form are also to be 
met with in the columella; in C. Smithii, for example, this organ is sometimes quite 
circular, although it is in general oblong. Differences of this kind, when not more marked 
than is the case among the various species of Cyathina, can therefore scarcely be deemed 
important enough to characterise generic divisions; and, as in the present case, they do 
not appear to coexist with any other structural peculiarity, we see no reason for admitting 
the new genus Amblocyathus. 
Pe Pabseix,wtiecaille 
? Note sur des Polypiers Fossiles, Paris, 1849. 
5 M. d’Orbigny employs the name of Albian formation to designate the Gault. 
