135 



madrepores or the alcyonia, seems to render this a fit place for their 

 consideration. An apology is, however, necessary for introducing in this 

 place, among these fossils, one or two which should, perhaps, rather have 

 been placed among the madrepores than among the alcyonia. This 

 has been done, in consequence of my collection of the Maestricht fos- 

 sils, not having been sufficiently important, at the time I was writing 

 my observations on madrepores, to authorize my speaking of them 

 from my own knowledge. Having since then acquired some very per- 

 fect specimens, I have ventured to introduce the examination of them 

 in this place, trusting that their very considerable deviation from the 

 madrepores we have previously seen, and their approximation to the 

 characters of alcyonia; with the difficulties which now oppose similar 

 specimens being brought into this country, may render their admis- 

 sion, although not exactly in their place, not unacceptable. 



St. Peter's Mountain, or Pietersberg, is situated within three quar- 

 ters of an hour's walk of Maestricht, forming an elevated escarp- 

 ment on one side of the Jaar, and being washed on the other by the 

 Meuse* On the side next to the Meuse, layers of a fine white sand,, 

 somewhat chalky, alternate with black, 'mamillated, and as it were, 

 ramified flints ; on some of which the regular organization of madre- 

 pores is plainly observable. Shells and wood are also found in this 

 part, impregnated with silex. This circumstance is the more de- 

 serving of attention, since the other side of the mountain, next the 

 Jaar, contains, chiefly, madrepores and shells, which are entirely cal- 

 careous, and in so perfect state of preservation, as sometimes to seem, 

 even to possess their original colour. 



The zoophytes which are found in the calcareous mass, which forms 

 this part of the mountain, particularly merit our attention. Not 

 only will the beauty of their forms, and the wonderfulness of theic 

 structure, engage our interest; but the vast difference observable be- 

 tween them and every other zoophyte of this, and of such as we have 

 seen of the former world, must call forth our utmost astonishment, So 



