368 TRANSACTIONS OF THE WAGNER FREE 



the insufficiently described and unfigured N. liimda Conrad may be identical. 

 This species has a rather prominent nucleus and a somewhat gibbous form. 

 The type is a rather elevated shell. The very young are marked on the um- 

 bilical callus with several transverse grooves, where most of the species of 

 Neverita have a single groove ; the character is peculiar, but somewhat variable. 

 These young shells have received the name oi arata from Gabb. Lea also de- 

 scribes, under the name of N. mamvia, a small depressed form, which may be 

 a variety of gibbosa, but which is without doubt the precursor of N. duplicate 

 in the Eocene, and is exactly reproduced in the Old Miocene of Shiloh, N. J. 

 Some of the young specimens from the Miocene retain the multiple grooving 

 of the callus in N. gibbosa, but most of them from the Chipola beds exhibit 

 rounded whorls, an excavated, spirally striated umbilicus only half filled by 

 the callus, which has its surface divided by a deep transverse sulcus. It is dif- 

 ficult to decide whether this form should be assigned, as a variety chipolmia, 

 to the Eocene gibbosa or to the Miocene duplicata, or whether it should be re- 

 garded as a distinct species from either. In any case it is an almost exactly 

 intermediate form between them. It reaches an altitude and diameter of 29 

 mm. and has been obtained from the lower bed at Alum Bluff and the Old 

 Miocene of the Chipola River. Another Eocene form which may belong in 

 this vicinity is the N. aperta Whitfield (not of Loven or Lea), which at first 

 sight would seem referable to the subgenus Mammilla, the umbilicus being 

 large and flaring, and in the young state at least entirely without a callus. 

 The form named N. onnsta by Whitfield, otherwise identical with his N. aperta, 

 has the umbilicus plumply filled by a rounded callus. One specimen in the 

 National Collection, among those which had been referred to N. aperta Whit- 

 field, has an incipient callus forming, and I am led to suspect that this species 

 delays forming a callus until the shell is fully grown and then adds it, and 

 that therefore N. aperta and N. onnsta should be consolidated under the last- 

 mentioned specific name. The species is found in the Eocene of Wood's Bluff 

 and Gregg's Landing, Alabama. 



Polynices (Neverita) duplicatus Say. 



Natica duplicata Say, Journ. Acad. Nat. Sci. Phila. ii. p. 247, 1822 



Neverita dupticata (Say) Dall, Bull. 37 U. S. Nat. Mus., p. 154, pi. 51, figure 12, 1889. 



Natica canipeachiensis (Recluz MS.) Reeve, Conch. Icon. Natica, pi. i, fig. i, 1855 ; Tryon, 



Man. viii. p. 34, pi. 13, fig. 10, 1886. 

 Natica texasiana Phil,, Zeitschr. f. Mai. for 1848, p. 158 ; Tryon, op. cit. p. 34, pi. 12, fig. 5, 



1 886. 

 Natica fossata Gould, Proc. Bost. Soc. Nat. Hist. ii. p. 263, 1847 ; Tryon, op. cit. p. 34, pi. 



12, fig. 4, 18S6. 

 Neverita EmmonsiiCoViX. , Am. Journ. Conch, iii. p. 259, pi. 24, fig. 2, 1867; Emmons,. 



Geol. Rep. N. C, p. 267, fig. 151, 1858. 

 Neverita densata Conr., Am. Journ. Conch, iii. p. 259, pi. 24, fig. 5, 1867 ; Emmons, op. cit. 



p. 266, fig. 150, 1858. 

 Natica percallosa Conrad, Am. Journ. Sci. xli. p. 348, 1841 ; Am. Journ. Conch, iv. p. 66, 



pi. vi. fig. 6, 1868. 



