328 



APPENDIX. 



Red Crag may with less probability be assigned to such a cause, as there is no good reason to believe that 

 the Mollusca in the remains of that Formation resided in very close proximity to the regions of fresh water. 

 The unnatural condition of the present specimen appertains more to the individual than either to a species 

 or to a colony, and may have arisen from some accidental circumstance, or from unsuitable food, or, what is 

 perhaps more likely, the unlucky animal may when young have been caught and retained in some confined 

 position, preventing its growth in a natural direction. It is an immature individual, although it has no 

 doubt been "curtailed of its fair proportions" in consequence of its deformity. 



Trophon antiquum, var. contrarium planorbulum. 

 From the Red Crag, Sutton. 



