78 TRANSACTIONS OF THE WAGNER FREE 



apical portion of the spire, which is much more distinctly papillated in 

 Valuta JjDionia, and on which the longitudinal sukation is but barely 

 visible. Although these characters are seemingly of not much import- 

 ance, they are, nevertheless, constant, and serve invariably to distinguish 

 the one form from the' other; were it not for them, I must admit that it 

 would be very difficult, if not impossible, to separate the two. The 

 Florida fossil appears, however, to attain a much larger size ; at least, I 

 have seen no specimens of the recent species that in any way begin to 

 compare with it, nor have I seen any figures or descriptions of the shell 

 that would lead me to infer that equally large specimens have ever been 

 found. Still, the same is not impossible, and I am informed by Mr. John 

 Ford, of this city, that, to the best of his recollection, specimens of Valuta 

 Jiinonia of the size above indicated had been seen by him. 



It is certainly an interesting circumstance to find a large volute so 

 nearly resembling the recent species, yet slightly differing from it, in a 

 geological formation antedating the present era by but a single period, 

 and in a region corresponding to the habitat of the living form, espec- 

 ially where no traces of the latter are to be found associated with it. 

 That the one is a modified descendant of the other we have, of 

 course, no direct means of proving, but the inference in that direction 

 is certainly very strong indeed, almost irresistible. To assume that the 

 Pliocene species should have become totally extinct before the modern 

 era, and been then followed by a specifically new form almost absolutely 

 its identical, as far as we are able to judge, and in a region which 

 appears to have undergone during the common period but little alteration 

 either in its physical or physiographical features, is barely consonant 

 with our present evolutionary conceptions, and certainly far less plausible 

 than the view which holds the interderivation of the two forms. The 

 latter supposition, apart from its own abstract position, is further strength- 

 ened by the similar resemblances which bind together other members of 

 the recent and extinct Floridian faunas. 



If, however, this species is interesting as indicating a probable line of 

 modification and descent progressionally, it is equally interesting as 

 indicating a similar line retrospectively, or one leading up to it from a 

 still earlier period. Thus, the species stands in-about as intimate relation 

 with the Valuta Trenholmi of Tuomey and Holmes, from the late Miocene 

 or Mio-Pliocene deposits of South Carolina, as it does with the recent 

 Valuta Junonia, and, indeed, might be properly considered to effect a 

 passage between the two. About the only distinctive character separ- 

 ating it from the older form, likewise, as far as we are permitted to judge 

 in the absence of color ornamentation and the animal itself, the one char- 

 acter separating the last from the recent species, is the less prominence 

 of the spire in V. Trenholmi, and a corresponding rise in the shoulders 



