58 BRITISH FOSSIL CORALS. 



This species is as yet the only known representative of our genus Peplosrailia, 1 and is 

 easily distinguished from the other true Eusmilinse, either by its lamellar columella or its 

 complete epitheca ; it may be considered as a Montlivaltia, having a lamellar columella. 

 We have seen but one specimen of this fossil ; it was found in the Greensand at Haldon, 

 and presented to the Geological Society by Mr. R. H. C. Austen. 



2. Genus Trochosmilia (p. xxiv). 

 Trochosmilia (?) tuberosa. Tab. X, fig. 2, 2 a. 



Turbinolia compressa, (?) Morris, Cat. of Brit. Foss., p. 46, 1843. 



Corallum simple, compressed, even at its basis, cuneiform, subpedunculated, and pre- 

 senting on each of its lateral edges, at a short distance above the basis, a broad but not 

 very prominent tuberosity. Costa delicate, straight, not prominent, but very distinct from 

 the basis upwards, closely set and somewhat unequal. Calice elliptic and horizontal ; its 

 small axis only half the length of the long axis. Fossula narrow, rather shallow, and 

 elongated. No columella. Septa forming five complete cycla ; very thin, straight, closely 

 set, and delicately granulated laterally ; those of the first and second cycla nearly equal in 

 size and larger than the others, so as to produce the appearance of twelve systems ; those 

 of the fifth cyclum very small. Height, seven lines • diameter of the calice, eight lines by 

 four. 



The above-described specimen was found in the Greensand of Blackdown by our able 

 friend Mr. J. S. Bowerbank. We have not, as yet, been able to ascertain the existence of 

 dissepiments in the interseptal loculi, and consequently are not quite sure that it belongs 

 to the genus Trochosmilia ; if these parts do not exist it must be referred to the family of 

 the Turbinolidse, but we have not had the materials necessary for deciding that question. 

 We shall therefore only add here, that this coral differs from the other species of Trocho- 

 smilia described in our ' Monograph of the Astreidae' by the existence of the lateral tubero- 

 sities, and the basis presenting scarcely any traces of adherence. 



It is probably this fossil which Mr. Morris referred to the Turbinolia compressa of 

 Lamarck, and mentioned as existing in the Greensand of Blackdown. T. compressa belongs 

 also to our genus Trochosmilia, and is found in the Greensand at Uchaux in the South of 

 France, but differs from T. tuberosa by its general form. 



1 The fossil described by M. Michelin under the name of Anthophyllum detritum (Icon. Zooph., tab. x, 

 fig. 1) might at first sight be supposed to belong to this genus, for it presents some appearance of a lamellar 

 columella ; but that is owing to the presence bf some extraneous matter adhering to the specimen figured by 

 M. Michelin, and although the epitheca does no longer exist in this fossil, we have no doubt that it is in 

 reality a Montlivaltia. 



