418 



ME. S. S. BTJCKMAlSr OlST 



[vol. Ixxviii, 



unrepresented by fauna — filled by strata of like or of unlike 

 character ? There is no evidence. 



The stratum of Posidonomya alpina of Sette Comuni (Ital}') 

 contains a fauna described and figured by Parona ^ which apj)ears 

 to show considerable mixture of Bajocian (and early Vesulian) 

 with Callovian species. Parona notes that such an admixture has 

 been recognized b}^ E. Bose & H. Finkelstein for the same stratum 

 in Southern Tj^-ol and b}'' E. Jiissen for the Klaus Beds of the 

 Northern Alps.^ In Parona's case the admixture seems to be greater 

 than he supposes, even allowing for the well-known and deceptive 

 homoeomorphy of certain Bajocian-Yesulian and Callovian species, 

 and therefore the following remarks on some of his faunal elements 

 may be of service. It is interesting to note how many of them 

 have a distinctly Bajocian-Vesulian aspect. Before claiming them 

 as Callovian species it would be very necessar}^ to show that they, 

 or very similar forms, occur in deposits which are unquestionably 

 Callovian. If that could be done, then they would still remain of 

 much interest, as illustrating heterochronous homoeomorphy. But 

 at present the majority of the forms about which the following 

 notes are made appear to be strangers to Callovian, though not to 

 Bajocian-Vesulian deposits. 



Table IV — Remarks ox Parona's Figured Species of 

 Bajocian-Vesulian Aspect. 



Reference. Species. 



Pl. I, fig. 11. ' Oppelia subtilicostata.' 



12. ' CEcotraustes minor! 



13. ' Cadomoceras nepos.' 

 14,15. ' Sphceroceras pilula.' 



16. ' SjpJicsroceras auritiim.' 



17. ' Spliceroceras ? disputahile. 



18. '' Stephanoceras rotula.' 



19. ' Stephanoceras ffibbum.' 



21. 'Stephanoceras venetum.' 



22. ' Far'kinso7iia honarellii. 



Pl. II, fig'. 1. ' Cosmoceras poUux.' 



Remarks. 



Similar to Oppelids of niortense 

 date. 



Possiblj'' a catamorph of Cado- 

 moceras. Of. C. costatum, I, 8, 

 pl. clxxxix : niortense . 



Good evidence for niortense date. 



Possibly catamorph of Lahyrin- 

 thoceras, I, 8, pis. cxxxiv, cxxxv ; 

 c. sauzei. 



Like species of hlagdeni-niortense 

 dates. 



Like species of niortense date. 



Like the coronate stage of Peri- 

 sphinctids of niortense-trneUei 

 date. 



Very like Trilohiticeras, I, 8, 

 pl. cxl ; Discites. 



Remarkably similar to Fohjplec- 

 tites sp of the truellei bed of ■ 

 Burton Bradstock. 



Not a Farkinsonia, as the furca- 

 tion is on the edge of the peri- 

 phery ; it should be about 

 medio-latei'al. A phaulomorph 

 Perisphinctid ; truellei? 



Like certain forms of Strenoceras 

 of niortense date. But there is 

 a great resemblance between the 

 Bajocian-Vesulian genera Stre- 

 noceras, Sacnlatoceras, Garan- 

 ^ia«a, and the Callovian Cosmo- 

 ceras in certain cases. 



VIII. 



2 VIII, p. 5. 



