440 TRANSACTIONS OF THE WAGNER FREE 



was truncated behind, and on the thick truncate margin of the posterior orifice 

 a sulcus was worn or produced by absorption in front and behind. Then the 

 animal changed his tactics, and, abandoning the attempt to modify the old 

 broken margin, secreted a small tube after the fashion of a "jury-mast." It 

 will be obvious to any one who inspects Dr. Meyer's figure that, after the 

 supplementary tube had been made the animal could not have produced the 

 sulci in the old margin outside of it. Consequently, the purely individual and 

 accidental nature of the characters of the posterior orifice as described by Dr. 

 Meyer cannot be denied. Very likely his shell represents a valid species, but 

 so far we have no means of identifying it except by specimens furnished by 

 the author. It is possible the smooth Miocene form may be different from D. 

 Danai, but we cannot be sure of this until complete specimens of the latter 

 liave been collected and described or distributed. 



Dentalium disparile Orbigny. 



D. disparile Orb., Moll. Cuba, ii. p. 302, pi. xxv. figs. 14-17, 1842 ; Dall, Blake Gastr., p. 



424, 1889. 

 D. antillarmn, this essay, p. 211 ; not of Orbigny. 



Older Miocene of the Chipola beds, Calhoun Co., Florida, and of the 

 lower bed at Alum Bluff, Burns ; Newer Miocene of North Carolina ; Pliocene 

 of the Waccamaw beds, S. Car., Johnson; of the Caloosahatchie beds, Florida, 

 Dall and WiUcox. 



This well-marked species at the posterior end is circular, with the exterior 

 crenulated by the ribs. By this feature it is distinguished from some of the 

 allied species whose posterior section is polygonal. It was inadvertently 

 referred to in the preface as D. antillarutn. 



Dentalium leptum Bush. 



D. Upturn Bush, Trans. Conn. Acad. vi. p. 470, p!. xlv. figs. iS, iS a, 1S85 ; Dall, Blake 

 Gastr., p. 421, 1889. 



Older Miocene of the Chipola River, Calhoun Co., Florida, Burns; living 

 from Cape Hatteras to Charlotte Harbor, Florida, in 2 to 50 fathoms, sand or 

 mud; U. S. Fish Commission. 



This pretty little shell will doubtless be found in the Newer Miocene and 

 Pliocene beds when sufficiently searched. The Chipola specimens do not seem 

 to offer any characters by which they may be discriminated from the recent 

 shell. 



Dentalium calamus Dall. 



Dentalium calamus Dall, Blake Gastr., p. 421, 1889 ; Bull. 37 U. S. Nat. Mus., p. 76, No. S, 

 1889. 



Pliocene of the Caloosahatchie, Dall ; living in four fathoms at Turtle 

 Harbor, Florida, Dr. Rush. 



