TRANSACTIONS OF WAGNER 

 7l6 



TERTIARY FAUNA OF FLORIDA \ 



obtained at Bowden ; the form and sculpture are practically the same, but the 

 ribs (twenty-one to twenty-five) are single, subequal, and not fasciculated, and 

 are separated by simple narrower interspaces not radially threaded. The 

 young of oniatns, as far as observed, seem to always have one or more inter- 

 stitial riblets. I therefore propose for the present form the varietal name 01 

 vagiintlus, which may be raised to specific rank if the difference is confirmed 

 by the characters of adult specimens. 



Pecten (Chlamys) interlineatus Gabb. 

 J'r/i-n inti-iiincatits Gabb, Geol. St. Dom., p. 256, 1873. 



Oligocene of St. Domingo; Gabb. 



Shell close to P. angnillcnsis Guppy, with about sixteen flatfish, eroded 

 ribs, with narrower interspaces containing a single thread ; the surface sculp- 

 tured with fine, wavy, concentric lamellae ; posterior two or three ribs under 

 the byssal notch are corrugated on the anterior edge ; submargins narrow, the 

 anterior smooth ; ears subequal, radially sculptured, notch deep. 



These notes are taken from the types of this unfigured species in the 

 collection of the Academy of Natural Sciences, Philadelphia. This may 

 prove to be identical with the specimen now standing as the type of P. 

 oxygomtm Sby. in the Heniker collection. 



Pecten (Chlamys ?) sp. indet. 

 l\ctcn opcrciilaris Gabb, Gcol. St. Domingo, p. 256, 1873 ; not of Linnc. 



Oligocene of St. Domingo; Gabb. 



This is a nearly smooth, ovate-oblong shell, with twenty-two nearly 

 obsolete ribs, fading out at the submargins ; ears small, low, subequal. Alt. 

 70, lat. 58 mm. It is obviously not the European species with which Gabb 

 too hastily identified it. 



Pecten (Chlamys) cactaceus n. s. 



PLATE 34, IMCIIKE 2. 



Tertiary of St. Domingo, Gabb; Pliocene of Tehuantepec, seventy kilo- 

 metres west of eastern terminus of the railway, near the foot-hills of the 

 elevated country, Spencer. 



Shell thin, fragile, compressed, nearly equilateral and equivalve, with ten 

 to twelve sharp, narrow-keeled ribs, with much wider shallow interspaces, 

 in which there are five or six fine, sharp radial threads; whole surface, when 



