ZURCHERIA. 



To the species in this remarkable and rare genus add Zurcheria 

 pugnax (Vacek). The specimen is a whorl larger than Vacek's, and 

 shews, on this whorl, the ornament of Haplopleuroceras sub- 

 spinatum, but with no trace of keel or furrow. It came from the 

 Building Stone of Stoke Knap, Dorset. 



StEI'HEOCKRATIDAE. 



Zigzagiceras. gen. nov. Type. Am. zigzag, d'Orb. 



A Stepheoceratoid series in which the umbilical, or lateral, 

 costae are distant and end in obtuse, elongate, somewhat angulate 

 knobs, instead of spines. Further development produces a planulate, 

 or Perisphinctean style of ornament, but without the periodic con- 

 strictions of Perisphinctes. 



On the developments of the zigzag series see Morphology of 

 " Steph." zigzag; Quart. Journ. Geol. See, vol. XLVIII., p. 447. 

 1S92. 



NORMAN, SAWYER AND CO., CHELTENHAM. JUNE, ig02. 



