10 



80 abundant in the Upper Lias both of England and continental Europe 

 is not altogether absent in the lower zone of the Sands. I have a single 

 specimen from Nailsworth. The number of synonyms is probably owing 

 to the varied forms which it assumes in the young state, some of these have 

 the sides much flattened and the back angulated, in others both sides and 

 back are gracefally curved; some examples have the costce delicate, regular, 

 and closely arranged ; others have the costce very unequal with deep and 

 distant sulcations between them, in this condition they are scarcely to be 

 distinguished from the young condition of A. elegans, Phillips, a species 

 which is quite distinct from the elegans of Sowerby. The adult forms of 

 A. complanatus on the other hand are very constant both in their figure 

 and ornamentation. 



There is also another radians-like Ammonite from the Upper Sands at 

 Frocester HiU remarkable for its tumid form, flattened sides and flattened 

 back, the keel is moderately prominent, and there is a slight depression 

 upon each side of it ; the costce are large, rounded, prominent, flexuose, 

 and very closely arranged, their prominence continues even upon the inner 

 margin of the volution, these several characters indicate a species distinct 

 from all the forms of radians and striatulus; unfortunately neither of the 

 two specimens at my disposal exhibit the septa, and, in the absence of all 

 other information, it would be unwise to tabulate it with the other 

 Ammonites, or to decide upon its stratigraphical limits. 



