GUELPH FAUNA IN THE STATE OF NEW YORK 53 



typical, and B. expansa has been construed as a species of Roemer's later 

 genus, Salpingostoma. De Koninck and Waagen, in the endeavor to define 

 the genus more clearly, based it on the presence of revolving lines. Koken, 

 who intimates that Hall when defining the genus evidently had before him 

 species of the subsequently established genera, Salpingostoma and Trema- 

 tonotus, bases the genus on B. sulcatina and defines it by its flat dor- 

 sum, wide umbilicus, slightly expanded peristome and coarse, wrinkled 

 revolving lines, crossed and interrupted by transverse lamellae. He also 

 includes in this genus the Devonic and Carbonic species bearing these char- 

 acters, and is followed in this view by Clarke, who has described a Devonic 

 Bucania. 1 Hall, on the other hand, states 2 that there are no Bucanias younger 

 than the B. profunda (which is a Trematonotus) of the Helderbergian, 

 so that there obviously exists a considerable difference between Hall's and 

 Koken's conceptions of Bucania. Lindstrom, in his work on the Silurian 

 Gastropoda of Gothland, does not recognize the genus at all, but unites it 

 with Bellerophon, on the ground that it has the wide aperture in com- 

 mon with most of the Bellerophons, and that the wide umbilicus and the 

 spiral striae are not of enough importance to be of value as generic distinc- 

 tions. The claim of Fischer 3 and Lindstrom, that Hall ultimately aban- 

 doned the generic term Bucania and reunited the form with Bellerophon, 

 seems to be based on a misconception, as Hall, in Paleontology of New 

 York, v. 5, states only that the B. devonica is probably not Bucania, 

 and that this genus does not enter the Devonic. 



In contrast with Lindstrom's extreme conservatism, Ulrich places Belle- 

 rophon and Bucania in different families, the Bellerophontidae and 

 Bucaniidae. He recalls Koken's observation as to the differences in the 

 aperture and surface sculpture between the " Sulcatina typus " and the 

 Devonic and Carbonic species, and holds the opinion that Bucania, in its 

 restricted sense, is " strictly a Silurian genus and possibly not even repre- 



1 Paleozoic Faunas of Para. 



2 Pal. N. Y. v. 5, pt 2. 



3 Manuel de Conchyliologie, p. 854. 



