224 CRETACEOUS LAMELLIBRANCHIA. 



Nou 1840. Panop^a gcrgites, A. Golclfiiss. Petref. Germ., vol. ii, p. 274-. pi. iliii, 



fig. 7 (P. G'oldfiisei, d'Orbigny, 

 1850). 



— — — PLicATA, Gohlj'iisn. Ibiil., p. 274, pi. olviii, fiyj. 5. 



— 1845. — G0RG1TIS, A. d'Orbigny. Pal. Fraiu;. Terr. Crt't., vol. iii, p. 345, 



pi. ccclxi, fiys. 1, 2. 



— 1846. — — A. E. Ueass. Die Versteiu. der bijluu. Kreideforiiuit., 



pt. 2, p. 17, pi. XXX vi, fig. 3. 



— 1847. — PLICATA, /, Mailer. Petref. der Aachen. Kreidef., pt. 1, p. 28 



{Glycliiieris Gehiitzl, Holzapfel). 



— 1873. — GTJEGiTis, H. B. Geinitz. Das Elbtluilgeb. iu Sachsen (Palaeouto- 



grapbica, vol. xx, pt. 2), p. (58, pi. xix, 

 figs. 1, 2. 



— 1876. — — D. Braiiiin. Zeitselir. f. d. gesammt. Naturvviss., vol. 



slvi, p. 362. 



— 1877. ■ — — A. Fritsch. Stud, im Gebiete der bohni. Kreideformat., 



ii, Weissenberg. ii. Maluitz. Scliicliten, 

 p. 125, fig. 100. 



— 1898. Glycimeris — G. Miiller. Die Mollusk. d. Uuterseuou v. Braim- 



selnveig u. Ilsede, p. 70, pi. x, fig. 4. 



— 1901. Panop/EA — F. Sturm. Jalirb. d. k. preuss geol. Landesanst. fiir 



1900, vol. xxi, p. 70, pi. X, fit;. 4. 



Description. — Shell more or less oblong, rounded, convex; posterior part 

 somewhat compressed, anterior part sloping more or less rapidly to the margin ; 

 moderately or considerably inequilateral ; i)Osterior gape large. Anterior margin 

 more or less convex, sometimes subtrimcate ; antero-ventral margin rounded; 

 ventral margin slightly or moderately convex, nearly parallel to the dorsal margin ; 

 posterior margin convex, or subtrnncate and rounded ; postero-dorsal margin 

 nearly straight. Umbones incurved, often broad, sometimes narrow and pointed ; 

 the dorsal part of the shell in front of the umbones is moderately or considerably 

 depressed ; sometimes a more or less distinct carina extends from the umbo 

 towards the antero-ventral extremity ; another carina, usually faint, may extend 

 from the umbo posteriorly. Pallial sinus large, rounded. 



Ornamentation consists of concentric folds, wliicli may l)c conspicuous or only 

 faintly indicated, and of nunicrons radial rows of minute granules. 



Measuremeiifs : 



(3) (4) (5) (.1) 



G9 . 65 . 01 . 5(5 

 :]G . 88 . 35 . 29 



(1, 5) Pec»a-bed, Atlierfield. 

 (3, 4, 6—9) Crackers, Atlierfield. 



(2) Ferruginous Sands, Sliankliu. 

 Affinities. — This species has been referred by most authors to the genus 



