ALLIES OF AMMONITES 



the Orthoceras, were not coiled but quite straight ; 

 others were loosely coiled, as is the Ancyloceras 



Fig. 195. — The shell of Ancyloceras matheronianum, from the 

 Neocomian (Lower Cretaceous) rocks of France. (Lent 

 by the Trustees of the British Museiim. ) A similar shell 

 is found in the Lower Greensand of the Isle of Wight. 



shown in Fig. 195, and others were twisted into 

 elongated spires (Turrilites). 



The creature which hved in these shells was 

 similar to a cuttle-fish (as we know from ex- 



269 



