1913 YORKSHIRE TYPE AMMONITES— II LXXIIc 



Fig. i 



Ammonites aculeatus, Simpson, 1843 



Whitby Museum, No. 177, Paratype 



Fig. 1, Apertural view ( x 0.6) ; Fig. 2, Suture-lines (Nat. Size) 



DEROCERAS ACULEATUM, Simpson sp. 



