INSTITUTE OF SCIENCE, PHILADELPHIA. 353 



The surface of this form recalls that of the typical TrocJiita, from which 

 it is probably not far separated, yet its intimate relation to the smooth species 

 precludes its being set off from them. These difficulties are such as we must 

 anticipate in following back diverging forms to their fossil progenitors. 



Calyptraea centralis Conrad. 

 Infundibulmn centralis Conr., Am. Jouni. Sci. xli. p. 348, 1841 ; Medial Tert., p. 80, pi. 45^ 



%• 5. 1845- 

 Trochita centralis Emmons, Geo!. N. C, p. 276, fig. 193, 1S58. 

 Infundibulum concentricum H. C. Lea, Trans. Am. Phil. Soc, 2d Ser. ix. p. 249, pi. 35, 



fig- 39. '84s ; young shell. 

 Trochita Collinsii Gabb, Joiirn. Acad. Nat. Sci. Pliila., 2d Ser. viii. p. 342, pi. 44, figs. 11, 



II a, 1875. 

 Infundibulum Candeaiium Orbigny, Moll. Cuba, ii. p. 190, pi. xxiv. figs. 28, 29, 1842. 

 Galerus Candeanus Dall, Hemphill's Shells, p. 335, 1883. 

 Galerus parvulus Dunker, Jahrb. Deut. Mai. Gas. 1875, p. 244. 

 Calyptrcsa Candeana Dall, Blake Report, p. 284, 1889. 



Fossil in the Older or Chipola Miocene at one mile below Bailey's Ferry, 

 Chipola River, Fla., Burns; in the Chesapeake Miocene at the Natural Well, 

 Duplin County, N. C, on the Peedee River, S. C, at Petersburg, Va., Sapote, 

 Costa Rica, and on the St. Mary's River, Md. ; in the Pliocene of the Caloo- 

 sahatchie beds, Florida; in the Pleistocene of South Carolina at Simmons's 

 Bluff; and living on the coast of the United States from Cape Hatteras south- 

 ward, in the Antilles and on the northern and eastern coast of South America, 

 south to Pt. Gallegos, not far from the Straits of Magellan, U. S. Fish Com- 

 mission. 



This species is well marked by a sort of umbilicus on the pillar, where 

 it is reflected, and by the arching forward of the free edge of the septum, 

 characters which have been exactly preserved since the early Miocene. The 

 only modification visible during the whole of that period, as represented by 

 a full series of specimens, is a slight increase of size from the earl)- to the 

 later Miocene, and a slight average decrease since, the recent specimens 

 being about the size of those from the Chipola beds, while those from the 

 Natural Well, Duplin County, are the largest. The differences, however, are 

 not great, and may be accidental to the particular locality rather than charac- 

 teristic of chronological changes. 



In addition to the species mentioned above, four species, C. costcllata and 

 Diegoana Conrad, filosa and inoniata Gabb, have been described from the 

 Miocene of California. A species which may prove to be a genuine Trochita 

 has been collected from the Older Miocene marl of Jericho, N. J. The speci- 

 mens have been so decorticated that it seems best to delay a description in 

 the hope of better material. Kw" Infundibulum carinatum" \\as been de- 

 scribed from the Eocene of Orangeburg, S. C. (Journ, Acad. Nat. Sci., 2d Ser. 

 i. p. 129, pi. 14, fig. 6, 1848). It is a fragment, and described as having a 

 carinated line at the suture — something unknown elsewhere in the group. As 



