69 



AMMONITES Planorbis. 



TAB. CCCCXLVIII. 



Spec. Char. Discoid, smooth; whorls three 

 or four, two thirds exposed. 



Few shells are more plain in their appearance than this 

 unornamented Ammonite, for its situation and analogy to 

 the following leave no doubt of its being an Ammonite, 

 although we have not met with the septae. It is always 

 found so much flattened that little can be added to the 

 specific description, for its thickness and the form of the 

 whorl cannot be ascertained ; we can only see that the 

 whorls encrease rather rapidly in diameter, that they 

 have no radii or tubercles, and that the striae of growth 

 are very fine. The inside pearly coat is nearly all that is 

 preserved, and that is sometimes very highly iridescent. 

 Not of very rare occurrence in a kind of slaty Clay 

 belonging to the Lyas beds, at Watchet. Fig. 1 is from 

 that locality. 



Fig. 2 is taken from, a high coloured individual said 

 to be from Lincolnshire, placed in Mr. Sowerby's cabinet, 

 by the Rev. R. B. Franciss, 



