PROTOCARDIA. 199 



? 1878. Protocardium Hili,anuivt, 0. Fraaf:. Ans deiii Orient. II Geol. Beobacht. 



am Libanon, p. 70. 

 1882. Cardium (Protocardium) Hillanum, P. de Loriol. Gault Je Cosne, p. 



69, pi. Tiii, fig. 17. 

 1884. Protocardium Hillanum, /. F. Whiteaves. Mesoz. Foss. (Geol. Surv. 



Canada), vol. i, p. 228, 

 pi. XXX, fig. 5. 

 P — Cardium (Protocardia) Hillanum, C. E. Hamlin. Mem. Mus. Comp. 



Zool., vol X, No. 3, p. 50. 

 1893. Protocardium Y{ua,,\nvm, R. Michael. Zeitschr. d.deutsch.geol.Gesellsch., 



vol. xlv, p. 232. 



1897. — — A.Fritscli. Stud, im Gebietederbolim. Kreide- 



format., vi, Chlomek. Schicht., 

 p. 52. 



— — — B,. Leonhard. Kreidef. in Oberscbles. (Pal- 



OBontograpliica, vol. xliv), p. 28. 



1898. — — A.Fritsch. Stud, im Gebieteder bobm. Kreide- 



format., iii, Iserschicht., p. 98. 



1901. Protocardia Hillana, F. Slnrm. Jabib. d. k. pieussisch. geol. Landes- 



anst. fiir 1900, vol. xxi, p. 79. 



1902. — — A. Quaas. Kreidebild. in der libysch. Wiiste 



(Palseontograpbica, vol. sxx, 2), 

 p. 218, pi. xxiv, fig. 18. 

 1904. — — B.. Fortnu. Bull. Instit. Egyptien, ser. 4, no. 4, 



p. 331. 



— — — var. UMKWEI.ANENSIS, R. Etheridge, jun. Second 



Rep. Geol. Surv. Natal and 

 Zululand, p. 79, pi. i, fig. 16. 

 1906. — — xdi:, H. Woods. Cret. Fauna of Pondolaud (Ann. 



S. African Mus., vol. iv), p. 3(i7, 

 pi. xxxvii, fig. 6. 



Deacriptiov . — Slioll convex, with flattened posterior slope, nenrlj- equilateral ; 

 outline more or Ic.-^s .suli-iiuadrate, rounded, .*ioinetimes ncarl}' oval; usually a 

 little higher than long, but raivly with the height and length erpial Anterior 

 margin eitliei- fairly conve.x and forming a rounded angle with the antero-dorsal 

 margin, or very convex and passing almost gradually into the antero-dorsal 

 margin. Anterior margin passes gradually into the ventral mai-gin, which may be 

 considerably convex, but is usually only slightly convex, with its posterior part 

 nearly straight and forming a more or less well-marked angle with the posterior 

 margin. The latter is truncated, slightly convex, and forms an obtuse angle with 

 the postero-dorsal margin. Umbones of moderate size. 



Ornamentation consists (except on the posterior part of the shell) of junnerons, 

 very regular, rounded, concentric ribs separated by narrow furrows; these ribs 

 become smaller or nearly obsolete near the antero-dorsal margin. On the posterior 



