CEPHALOPODA. 89 



face structures produced by the formative membrane and not due 

 to decomposition as in B. acuarius macer, Quenst., for the striae are 

 very regular and are best developed where the surface has suffered 

 least in fossilization. 



The form too is sufficient to distinguish it from other Cre- 

 taceous Belemnites, while yet other specialities are probably indi- 

 cated by the condition of the curious proximal cavity. We find 

 therefore in this Belemnite several such important special features 

 as suggest that we have here the type even of a new genus of 

 Belemnitidae. 



Locality. Upware. 



AMMONITES CORNUELIANUS, d'Orbigny. 

 (Plate i., fig. 9, a c.) 



Ammonites Cornuelianus, d'Orb., Terrains Cr&aces, I., pi. 112, 

 f. 1, 2, p. 364. 



Pictet and Roux, Mollusc des Ores 



verts, pi. v., f. 4, a, b, p. 55. 



Ooster, Fossiles des Alpes, iv., Cepha- 



lopoda, p. 132 (Bernese Alps). 



A variable Ammonite, belonging to a variable group the 

 Nodosocostati (P. and C.). It is closely allied to our Atherfield 

 Am. Martini (d'Orb.) with which it has been bound up by MM. 

 Pictet and Campiche in the above-named group. Quenstedt unites 

 this species and Martini with verrucosus d'Orb., (Quenst. Petrifac- 

 tenkunde, Vol. I., p. 136). Am. Martini is a thicker form, less open, 

 than our species, and the spines are better developed in the later 

 whorls. In the Woodwardian specimen the spines are well de- 

 veloped on the younger whorls but become obtuse and rather 

 obscure further on. 



Two varieties occur at Upware, a rotund variety (A) (round 

 whorled) and a flatter whorled form (B) ; the latter approaches 

 A. Milletianus, d'Orb. 



The sharply defined, obtuse, square-sectioned ribs, especially 

 over the back, are very characteristic of this group of Ammonites. 



Our three best specimens (Woodwardian Museum) measure 

 about 3 inches, 1 and f inches respectively. 



