328 CRETACEOUS LA.MELLIBRANCHIA. 



1850. Inoceramus involutcs, J. de C. Sowerly, in F. Dixon. Geol. Sussex, p. 



355 (p. 386, ed. 2), pi. xxviii, fig. 32. 

 1854. — —J. Morris. Cat. Brit. Foss., ed. 2, p. 169. 



1863. — — A. V. Siromhecl: Zeitscbr. d. deutsch. geol. 



G-esellsfli., vol. xv, p. 127. 

 1871. — (VoLvicER.^Mfs) INVOLUTUS, F. StoUczkii. Pulwout. ludica, 



Cret. Faumi S. ludia, vol. 

 iii, pp. 394, 401. 



1875. — INVOLUTES, C. Df'cocq. Assoc. Franc. Avaiic. Sci. (Lille, 



1874), p. 367. 



1876. — — D. Bra II III!. Zeitselir. f. d. gesanimt. Naturwiss., 



vol. xlvi. p. 379. 



1877. — — C. Svlil'^ter. PAl8eoutoi,'raplii(.-a, vul. xxiv, ].. 27-_'. 



1878. — — C. Barrois. Ann. Soc. gi'ul. du Nord, vol. v, 



p. 475. 

 1888. — • (VoLviCEUAMUs) IN'VOLUTUS, Cr. .W/(7/(>/-. Jalu'b. d. k. preus.s. 



geol. Landesanst. fiir 1887, p. 411, 

 pi. xvi, figs. 3, 4. 

 — — ixvoLUTUs, A. Pemii. Hist. Terr. Craie S.E. du Bassiii 



Auglo-Pai'isien, p. 157. 



1901. — — F. Sliinii. Jalirb. d. k. preuss. geol. Landesanst. 



fiir 1900, vol. xxi, p. 91, pi. ix, fig. 4. 



1902. — — A. Wolleiiianii. Liineburg. Kreide (Abliaudl. d. 



k. prtuss. geol. Landesanst. 

 N.F., 37), p. 68, pi. i, fi;,'. 4; 

 pi. ii, figs. 7, 8. 

 1906. — — G. Smolei'igM. Bull. Intern. Acad. Sci. Cracovie, 



p. 721. 



1909. — — J. Nnwal: Ibid.. \<. 874, pi. xlvi, figs. 4, 5. 



1910. — — J. Bvhin. CVntralbl. fiir Min., etc., p. 741. 



DescrlpHon. — Bliell very iiu'(|uivalvr and wvy iiiequilatei-al. Riglit valve oval 

 or semi-oval in outline ; usually slig'litly coiive.x. I)ut .sometimes either more convex 

 or nearly fiat, with the uuirginal part in old specimens forming an obtuse angle 

 with the earlier part, liength greater than height. Anterior and ventral margins 

 rdunded ; posterior margin forming usually an obtuse angle l)ut sometimes nearly 

 a right angle with the hinge. Umbo usually incdnspicuons, at or near the 

 anterior end of the hinge-line. Hinge-line e(iuals about thrt'c-cpiarters of the 

 length of the valve. Postero-dorsal nuirginal part convex near the hinge and 

 separated by a sharp furrow from the remaimlei' of the \alve. Ornamentation 

 consists of strong, somewhat irregular concentric folds, with an un.symmetrical 

 curvature; the folds are sej^arated l)y broad, concave interspaces. In casts of this 

 valve, ami sometimes in the shell itself, radial markings ai'e seen in the concave 

 interspaces. 



Left valve much lai-ger than the right, inflated, more or less considerably 



\ 



