rs 



EARTH 

 CLASS PELECYPODA (CONT.NUBD) S5!? 1 



Subgenus GRYPH/EOSTREA Conrad 

 [Am. Jour. Conch., vol. i, 1865, p. 15. Name only] 



Type. Ostrea subeversa Conrad = Gryphcea vomer Morton. 



" Shell thin, elongate, straight, narrow ; lower valve rather deep and 

 smooth; upper valve flat or slightly concave, and ornamented with distant, ' 

 regular, thin, concentric laminae; beak of lower valve contorted, or 

 turned to one side ; cartilage-pit narrow, oblique. Gryphcea vomer Morton 

 (sp.). Mr. Conrad did not publish a diagnosis of this type, but merely 

 gave the name in a list of fossils. At my request, however, he gave me in 

 manuscript the above diagnosis, and mentioned the above type. I would 

 add that, in perfectly preserved specimens, the typical species presents 

 the singular peculiarity of throwing out long, slender, auricular appen- 

 dages (one on each side) from the lower valve near the beak. These being 

 very fragile, are nearly always broken away, as the specimens are found; 

 but I observed several, with more or less of them preserved, in the New 

 Jersey beds ; and one I found growing in the inside of a Gryphcea vesicu- 

 laris with them perfectly preserved and apparently attached to the 

 Gryphcea by their extremities." Meek, 1876. 



Gryphceostrea suggests Exogyra in the gyrate umbones of the left valve, 

 The beak of the right valve of the former, however, is orthogyrate or at 

 the most slightly inclined, and this, together with the inflation of the 

 beak of the left valve, allies it more closely with Gryphcea than with 

 Exogyra. 



(GRYPH^OSTREA) VOMER Morton 

 Plate XXV, -Figs. 1-4 



Gryphcea vomer Morton, 1828, Jour. Acad. Nat. Sci., Phila., vol. vi, p. 83. 

 Gryphcea vomer Morton, 1834, Syn. Org. Rem. Cret., p. 54, pi. ix, fig. 5. 

 Gryphcea vomer Conrad, 1835, Trans. Geol. Soc., Pennsylvania, vol. i, p. 336. 

 Gryphcea vomer Conrad, 1842, Proc. Nat. Inst., Bull, ii, p. 172. 

 Exogyra lateralis Meek, 1864, Check List Inv. Fossils N. A., Cret. and Jur., 



p. 6. 

 Ostrea (Gryphceostrea) subeversa Conrad, 1865, Am. Jour. Conch., vol. i, 



p. 15 (name only). 



Etymology: 7pii7r6y, hook-nosed; ostrea, oyster. 



