1869. 



1876. 



PHOLADOMYA. 251 



1850. Pholadomya decussata, A. AW,. Geogu.-pateont. Bescbreib. v. Lemberg 



(ibid.), IX 236. 

 ^^^^- ~ —J. Morris. Cat. Brit. Foss., ed. 2, p. 220. 



^^*'^- — — var. TRixaavhARiH, H. G. Seeley. Anu.Mag.Nat. 



Hist., ser. 3, vol. vii, p. 122. 

 1863. — (CARmvM.)DECvsaArA, A. v.Stromheck. Zeitschr. der deutscb. 



geol. Gresellscb., vol. xv, p. 143. 

 1865. — DECUSSATA, F. J. Pictet and G. Campiche. Terr. Cret. Ste. 



Croix (Matt'r. Pal. Suisse, ser. 4), p. 94. 

 — — E. Favre. Moll. Foss. de la Craie de Lemberg, 



p. 106. 

 1875. — _ A. J. Jukes-Browne. Quart. Joum. Geol. Soc, 



vol. xxxi, p. 300. 

 ~" — — C Moesch. Mon. Pboladomven, p. 107, pi. xxxii, 



figs. 5 ?, 6 ; pi. xxxvi, figs. 5, 6. 

 — D. Brauns. Zeitschr. f. d. gesammt. Natm-wiss., 



vol. xlvi, p. 361. 

 ? 1889. — _ j;. Hohapfel. Die Mollusk. Aacbeu. Kreide (Pal- 



eeoutographica, vol. xxxv), p. 164, 

 pi. xiv, figs. 3, 4. 

 1891. — — J.Buhm. Kreidebildimg. d. Fiirbergs u. Sulz- 



bergs (Palseoutograpbica, vol. xxxviii), p. 73. 

 1893. — — A. Fritsch. Stud, iiu Gebiete der bolim. Kreide- 



foi-mat. V. Prieseu. Sebieht., p. 97, fig. 116. 

 ? 1898. — — G. Mailer. Mollusk. d. Uutersen. v. Brauuscbwei" 



u. Ilsede, p. 74, pi. x, fig. 3. 

 1^01. — — A. Wollemajin. Jabrb. d. k. preuss. geol. Laudes- 



aust. fiir 1900, vol. xxi, p. 22. 

 1902. — -- A. Wollemanit. Liiueburg. Kreide, p. 79. 



Nou 1829. — — /. P},inq»<. Geol. Yorks., pp. 122, 186 (p. 255, 



ed. 3), pi. ii, fig. 9. 



— 1842. — — L. Agassiz. fitudes crit. Moll. Foss., Myes, p. 74, 



pi. iv, figs. 9, 10 ; pi. iv', figs. 7 — 11. 



— 1843—50. — — G. P. Desluiy:.-'. Traitc Ek'meut. de Couebyliol., 



vol. i, pt. 2, p. 158, pi. V, fig. 5. 



— 1849. — —A. (VOrhhjntj. Prodr. de Pal, vol. i, p. 335. 



Distribution. — Shell large, inflated, with the greatest diameter at the anterior 

 end, outline .semi-ovate (sometimes sub-trigonal), wedge-shaped behind, extremely 

 inequilateral, with a ^^nlall posterior gape; height and length often nearly equal. 

 Ventral margin slightly curved. Posterior margin rounded. Anterior part of the 

 shell very short, flattened, with cordate outline, nearly perpendicular to the plane 

 between the valves, and forming almost a right angle with the sides of the valves ; 

 the margin of the anterior part is more or less angular, and just within is a 

 shallow concave part parallel to the margin, whilst the median part is convex, and 



