228 CRETACEOUS LAMELLIBRANCHIA. 
dD. 
PANOPEA MANDIBULA (Sowerby), 1813. Plate XXXVII, figs. 1 
1813. Mya manprsuna, J. Sowerby. Min. Conch., vol. i, p. 98, pl. xliii. 
? 1840. Panopma Baumontit, A. Goldfuss. Petref. Germ., vol. ii, p. 274, pl. elvi, 
fig. 4. 
? 1841. — JuaueErti, fF. A. Rimer. Die Verstein. d. nord-deutsch. Kreidegeb., 
p. 75, pl. x, fig. 4. 
1845. — MANDIBULA, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. ii, p. 344, 
pl. ecelx, figs. 3, 4. 
1850. — -— H. B. Geinitz. Das Quadersandst. oder Kreidegeb. 
in Deutschland, p. 146. 
1854. Myacrres manpisuta, J. Morris. Cat. Brit. Foss., ed. 2, p. 213. 
1865. Panopma ~- F. J. Pictet and G. Campiche. Terr. Crét. Ste. Croix 
(Matér. Pal. Suisse, ser. 4), p. 70. 
1870. = — F. Stoliczka. Paleont. Indica, Cret. Fauna 8. India, 
vol. in, p. 87. 
1873. -- a H. B. Geinitz. Das Elbthalgeb. in Sachsen (Pal- 
eontographica, vol. xx, pt. 2), p. 
70, pl. xviii, figs. 20, 21. 
? 1883. — — A. Fritsch. Stud. im Gebiete der bohm. Kreide- 
format., ii, Iserschicht., p. 108. 
P 1897. — oe Fritsch. Ibid., vi, Chlomek. Schicht., p. 60. 
1900. PLEevuROoMyYA — A.J. Jukes-Browne. Cret. Rocks of Britain, vol. 1, 
p. 470. 
Description. — Shell oblong or rhomboidal in outline, very inequilateral, 
convex, anterior part sloping rapidly to the anterior margin, with a wide posterior 
gape. Anterior margin somewhat convex; antero-ventral extremity rounded ; 
ventral margin straight or slightly curved and nearly parallel to the dorsal 
margin; postero-ventral extremity rounded ; posterior margin truncated, nearly 
straight, either perpendicular or slightly oblique to the nearly straight postero- 
dorsal margin. Umbones prominent, narrow, pointed, considerably incurved, 
with a broad, shallow furrow extending from their posterior side to the postero- 
ventral part of the valves. In front of the umbones the shell 1s considerably 
depressed. 
Ornamentation consists of strong, rounded, concentric folds, which become 
less distinct in and posterior to the dorso-ventral furrow; and of radial rows of 
minute granules. 
Measurements : 
(1) (2) (3) (4) (5) (6) 
encthe "Sy 7250 VO C..08 7 90. 49°. 386anm.- 
Heigit os loves) 46, 2 4) 88. . 85>. 33°. 
Thickness. 41 39 — Ou te Oe Bere vs 
(1, 4—6) Upper Greensand, Ventnor. 
(2, 3) Upper Greensand, Devizes. 
