74 THE NAUTILUS. 



ancestor of Futyur, the latter being first represented in the Oligocene 

 and Lower Miocene by F. spiniyer and its several varieties, and in 

 the middle Miocene by F. fusiform* 8? 



From this form was probably derived, as Mr. Grabau states, "the 

 large and ponderous Fulgur maximum Conr.," which apparently, 

 through the varieties tritonis andflosum* leads to the recent F. carica 

 and its variety eliceans. On the other hand, the sinistral form un- 

 doubtedly evolved from F. maximum in the upper Miocene much 

 earlier than Mr. Grabau's table would imply, and by forms such as 

 F. adversarium and F. obfilosum leads directly to the recent F. perver- 

 sum, and its rare variety kieneri Phil, presenting exact parallels to 

 the F. tritonis jilosum and F. carica eliceans series, thus strengthening 

 the theory of a common ancestry. During the Pliocene, F. pvrcer- 

 sum seems to have extended and found more favorable conditions 

 further south, for it is really more plentiful and better developed in 

 the Caloosahatchie than in the Waccamavv beds. On the gulf coast 

 at the present time it is more abundant than on the Atlantic, while 

 F. carica is not found at all in the Gulf of Mexico. 



In the Caloosahatchie beds there appeared a new form, F- rapum 

 Heilp., probably derived from F. perversum (as such forms of perver- 

 sum as Mr. Grabau has called obrapum would indicate) and appar- 

 ently representing a reversion to the maximum type. 



\ would not consider obrapum to be sinistral rapum, neither would 

 I consider obfilosum to be a sinistral Jilosum; for while admitting a 

 common ancestry, the immutability of the recent perversum and 

 carica has given us reason to believe that the same stability has ex- 

 isted since they originated. To admit the mutability of sinistral and 

 dextral forms only makes " confusion worse confounded." F. rapum, 

 through the form tritonoides Grabau, leads to the recent F. coarcta- 

 tum Sowerby of the Gulf of Mexico, an extremely rare shell which 

 may possibly be extinct. The long anterior canal of the monstrosity 

 F. candelabrum. Lam., as figured by Kiener, indicates a position here, 

 rather than under eliceans. 



1 In a bed which overlies the Chipola and having an out-crop in a mill-race 

 two miles east of Argyle, Fla., I found this species, identical with specimens 

 from St. Mary's, Md. 



2 F. Jilosum did not originate in the upper Miocene, as indicated by Mr. Gra- 

 ban's table; F. maximum, tritonis and Jilosum are all associated with F. indie at 

 Yorktowu, which moreover is the type locality for filosum. 



