37 



TAB. CCCXXIII. 



CALX carbonata. 

 Coralloid Limestone. 



Div. 2. Imitative. 



Steeple-Ashton, Calne hi Wiltshire, and the neighbour- 

 hood, afford vast quantities of Coral Rock, most of which 

 has the common appellation of Coral Paste. It is frequently 

 semi-transparent with a waxy appearance, and the Corals 

 impregnated or cast in it often help the deception. In well- 

 chosen pieces it takes a fine polish, and often exhibits the 

 structure of the Corals and other things which it contains, 

 very beautifully, either like those found in Flint, tab. 291, 

 or some other species, of which there seems to be a great 

 number. The present specimens somewhat resemble, and 

 are even more instructive than those from St. Peter's 

 mountain near Msestricht, which seem to have been con- 

 tained in a very similar stratum. It appears that the nature 

 of these Coralloid Fossils has not been determined — see 

 Parkinson's Organic Remains, PI. xii. 1. 2. This speci- 

 men shows that they ought to be considered as casts with 

 regard to the Coral, which is evinced by the sttllce on the 

 case of the Mytilus, which, for the sake of distinction, I shall 

 call M. tunicaius. On uncovering some of these I found 

 specimens sufficiently perfect to develop the truth, they 

 having been often considered as Pkolades, and lately as 

 Alcyonia; but we must not allow of too much latitude for 

 hypothesis. 



The upper corner figure is one of the cased Myiili co- 

 vered with remarkably formed crystals of Carbonate of 



