24 PERMIAN FOSSILS. 



The original description, which appeared in the ' Beitrage/ of Petraia being so 

 imperfect, — Count Miinster having drawn it up under the belief that he was describing 

 a genus of Gasteropodous shells, — I have been compelled to adopt the diagnosis given 

 by the author of the ' Palseozoic Fossils of Cornwall, &c/^ The views, too, of Professor 

 Phillips on the analogies of this genus may very appropriately follow as a pendant. 

 " In the single unattached mass and denticulated lamellge of unequal lengths, we see 

 the closest analogy with Fungia and Turbinolia (with the latter of which they have 

 been commonly united) ; while the deeply concave, lamelliferous disc and the absence 

 of horizontal septa seem to give generic peculiarity. The lamelloe are not granular 

 on their sides." 



The genus is not known to occur in a recent state : all the species that have been 

 described belong to the Palaeozoic formations, unless we include in it the Anthophylluvi 

 venustum of Miinster found in the (?) Triassic beds of St. Kassian. 



Petraia profunda, Germar. Plate III, fio-. 2. 



(?) AsTR^A PEDICUJLATA, B. Phillips, Encyc. Met. vol. vi, p. G15, 1834. 

 (?) A Lamelliferous Coral, Phillips. Lardner's Cycl. Geology, vol. i, p. 190, 1837. 

 Cyathophyllum profundum, Germar. Versteinerungen, p. 37, 1840. 



— — „ Geinitz, N. Jahrbuch, 1842, p. 579, pi. x 



fig. 14a. 



— — „ Geinitz, Gsea, von Sachsen, p. 98, 1843. 



— — „ DeVerneuil, Bull. Soc. Geol. France, 2""' serie, 



vol. i, p. 23, 1844. 

 Petraia n.s.. King, De Verneuil, Op. cit. 



— — „ Geol. Russ. vol. i, p. 221, 1845. 



Cyathophyllum profundum, Germar. Op. cit. 

 Petraia dentalis. King. Catalogue, p. 5, 1848. 

 Caryophyllia guadrifida, Howse. T. N. F. C. vol. i, p. 260, 1848. 

 Cyathophyllum profundum, Germar. Geinitz, Versteinerungen, p. 17, pi. vii,fig. 7, 1848. 



I)ia(/nosis. — " Form conical, and slightly curved. Cavity deep, and longitudinally 

 furrowed. Plates of two lengths ; the longest five or more in number, plain edged ( ?) 

 and reaching half way to the centre ; the shortest from one to four in number. 

 Lamellar interspaces with two very finely-denticulated, slightly prominent ridges."^ 

 The following description of Petraia profunda is copied from Geinitz : 

 " Umgekehrt lang-kegelformig mit tief herabgehender konischer Miindung. Die 

 starken Liingslinien der Oberfliiche, deren man auf einer Hiilfte oben gegen fiinfzehn 

 ziihlt, werden unregelmassig und hiiusig durch concentrische erhoete und vertiefte 

 Wachsthumsringe und Linien unterbrochen. Das untere Ende des Ganzen ist 

 gewohnlich etwas seitwarts gebogen. Die Miindung geht bis zur Mitte der Hohe, 



1 Palaeozoic Fossils of Cornvrall, &c,, p. 1. 



2 King, Catalogue, p. 5, 1848. 



