FREE INSTITUTE OF SCIENCE 



73S 



TERTIARY FAUNA OF FLORIDA 



haps II represent badly worn P. phiygitcm, while figs. 8 and 9 are taken 

 from the worn type of P. glyptics. Perfect specimens of the latter are in the 

 National Museum and were figured as above cited in its Proceedings. It is 

 not yet known in the fossil state. 



Peoten (Chlaniys) islandicus Miiller. 

 PecU'H islandicus Miiller, Prodr. Zool. Dan., p. 248, 1776. 

 Ostrea cinnabarina Born, Test. Mus. Vind., p. 103, 1780. 

 Pecten rubidtis Maxtyn, Univ. Conch., No. 153, pi. 53, fig. i, 1784. 

 Ostrea demissa Solander, Mus. Calonn., p. 52, 1797. 

 Pecten Peateii Conr., Am. Mar. Conch., i, p. 12, pi. 2, fig. 2, 1831. 

 Pcctcn Fabriiii Phil., Abb. und Beschr., iv., p. 3, pi. i, fig. 5, 1S44. 



Chlamys costcllata Verr. and Bush, Trans. Conn. Acad., x., p. 75, 1897. (Very young 

 shell.) 



Pleistocene of New England and New Brunswick and northward in the 

 bowlder clays, also on the North Pacific coasts in deposits of the same age ; 

 living from the Arctic waters southward to Chesapeake Bay. 



The minute shell described by Professor Verrill under the name of cos- 

 tcllata is less than five millimetres long and has not assumed the adult char- 

 acteristics. From an examination of the type I see no reason to doubt that 

 it is a very young specimen of the present species. This shell is the type of 

 the subgenus Chlamys. 



Pecten (Ohlarnys) Kneiskerni Conrad. 

 Pecten Kneiskerni Conr., Am. Journ. Conch., v., p. 40, pi. i, fig. 18, 1869. 

 Pecten Kneiskerni Whitdeld, Lam., N. J., p. 224, pi. 29, fig. 5, 1885 ; in part. 



Eocene marl of Shark River, New Jersey, Conrad ; Jacksonian Eocene of 

 Claiborne, Alabama, and Enterprise, Mississippi, Johnson; Oligocene of the 

 Chipola beds, Monroe County, Florida (?), Burns. 



In Professor Whitfield's attempt to identify the cast of an immature shell 

 named as above by Conrad, the foriner has evidently brought together the 

 young, uncharacteristic shells of several species of Chlamys. Conrad's shell 

 was described as having thirteen ribs and none on the subtnargins ; Whitfield 

 gives the species fifteen to fifty ribs and radiated submargins. This is a range 

 altogether too great for a single species. Probably some of Professor Whit- 

 field's specimens were young choctavcnsis, which has an unusually large 

 number of ribs. I have supposed a shell from the Jacksonian might represent 

 the unidentifiable species of Conrad. This has twenty-five ribs, divaricating 



