CRANIA. 11 



4. Crania Egnabergensis, Betzius. Plate I, figs. 8 — 14. 



Numulo . . . . ? Stobceus. Dissert, de Numulo Brattenbergensis, 1732, pi. i, 



figs. 3-4; and Opuscula in quibus Petrefactorum, 1753, 



tab. 1, figs. 3-4. 

 Crania Egnabergensis, Retzius. 1 Crania Oder., &c, in Berlin Geselisch Schaft, 



vol. ii, p. 75, tab. i, figs. 4, 7, 1781 ; Encyclop. Meth., 



pi. 171, figs. 6-7, 1789. 

 Crania striata, Defrance. Diet, des Sc. Nat., p. 315, No. 2, (non Nilsson, 1827,) 

 1818. 



— — Lamarck. An. sans Vert., vol. vi, p. 239, No. 5, 1819. 

 Anomites craniolaris Egnabergensis, Wahlenberg. Petref. Telluris Svecanse exami- 



nata in Nova Acta Societatis Scientiarum 

 Upsaliensis, vol. viii, p. 60, 1821. 

 Crania striata, Hoeninghaus. Beitrag zur Mondergattang Crania, No. 10, fig. a, 1828. 



— — and C. ovalis, Woodward. An Outline of the Geol. of Norfolk, pi. vi, 



figs. 15-16, 1833. 



— striata, Beshayes. Nouv. Ed. de Lamarck, vol. ii, p. 19, No. 9, 1836. 



— — Hisenger. 1837? Lethea Succ, p. 84, pi. xxiv, fig. 10. 



Crania Egnabergensis, Bronn. Lethea Geog., vol. i, p. 665, tab. xxx, fig. 2, 1837. 



— — Roemer. Die Vers. Norddeutschen Kreidgeberges, p. 36, 



No. 6, 1840. 

 Crania striata, Goldfuss. Petref. Germ., p. 295, pi. 162, fig. 10, 1840. 



— ovalis, striata, spinulosa, Morris. Catalogue, 1843. 



— Ignabergensis, If Orb. Pal. Franc. Ter. Cretacees, vol. iv, p. 142, pi. 526, 



figs. 1—6, 1847. 



— striata, spinulosa, Tennant. A Stratigraphical List of British Fossils, 1847. 



— — Dixon. The Geol. of the Ter. and Cret. Formations of England, 



pi. xxvii, 1851. 



— Ignabergensis, D'Orb. Prodrome, vol. ii, p. 259, 1850. 



Diagnosis. Shell irregular, inequivalve, circular, both valves presenting a more or less 

 conical depressed shape; apex submarginal, nearest the posterior edge attached by a small 

 or large portion of its lower valve to shells or corals, principally at or near the vertex of 

 the lower valve. Surface ornamented by a variable number of costse, radiating irregularly 

 from the vertex in both valves, and after reaching the edge, pass it, forming a number 

 of asperities all round, these likewise augmenting in number by the addition of smaller 

 costae appearing at a variable distance from the vertex, and irregularly intercalated between 

 the larger ones ; concentric lines of growth are also visible intersecting the striae ; the 

 upper valve is most convex or conical ; the interior of the lower valve is surrounded by a 

 wide, rather flat, strongly granulated margin ; four muscular impressions ; the two pos- 



1 Retzius gives, in 1781, four good figures of his Crania Egnabergensis, and refers to the two 

 illustrations published by Stobaeus in 1732, under the name of Numulo ; but the figures of this last author 

 are not sufficiently detailed to be identified with certaiuty. I am fully convinced, however, that his fig. 4 is 

 the same as that described afterwards by Retzius. 



