CORAX. 201 



Horizons and Localities. — Zones of Mavsvpites {VinfacrinvsAmnil) and Actino- 

 caviax quadratus : neigliLourliood of Salisbury, Wiltshire. Also from Chalk of 

 Kent. 



4. Corax aflBnis, Agassiz. PI. XLIII, figs. 4 — 0. 



1843. Corax affinis, L. Agassiz, Poiss. Foss., vol. iii, p. 227, pi. xxvi, fi^. 2, pi. xxvi a, figs. 21 — 24. 



1843. Corax appendiculatus, L. Agassiz, torn, ctt., p. 227, pi. xxvi, fig. 3. 



1843. Corax planus, L. Agassiz, tarn, cit., p. 229, pi. xxvi a, figs. 51 — 57. 



1854. Sphy ma plana, E. Hebert, Mt'm. Soc. Geol. France [2], vol. v, p. 354, pi. xxvii, fig. 9. 



1889. Corax a finis, A. S. Woodward, Catal. Foss. Fishes B. M., pt. i, p. 427. 



1894. Corax affinis, A. S. Woodward, Proc. Cleol. Assoc, vol. xiii, p. 199, pi. vi, figs. 19 — 22. 



1897. Psemlocorax affinis, F. Priem, Bull. Soc. Gcol. France [3], vol. xxv, p. 46, pi. i, figs. 20—27. 



1902. Pseudocorax ajfinis, M. Lericlie, Ann. Soc. G-col. Nord, vol. xxxi, p. 122, pi. iii, figs. 79 — 86. 



1906. Pseudocorax affinis, var. l;evis, M. Lericlie, Mem. Soc. Gc'ol. Nord, vol. v, p 80. 



Type. — Detached teeth from the Danian of Maastricht, Holland. 



Specific Characters. — Teeth comparatively small, the cro\yn more slender and 

 elevated than in the other species, notched prominently ' at the base of the 

 hinder border and less so at the anterior border, thus producing a broad posterior 

 denticle and a less distinct anterior denticle; serrations feeble or absent. Root 

 Avith a slight median cleft for a nutritive foramen on its inner face. 



Description of Specimens. — The margins of the typical teeth from the Danian 

 of Maastricht seem to be always distinctly serrated; while those of the teeth from 

 the Upper Senonian of Belgium, France, and England are merely very thin, often 

 crimped or jagged, but not truly serrated. Leriche (1906) therefore regards the 

 earlier teeth, such as those now to be described, as belonging to a well-marked 

 variety, which he names Ja^ris. The upper part of the dental crown is sometimes 

 sufficiently translucent to show by transmitted light the mineral-stained coarse 

 network of vascular canals, which traverse the internal core of vaso-dentine. 

 Sections have proved that there is no internal cavity. 



An anterior tooth (PL XLIII, fig. 4) has the crown only slightly inclined, Avith 

 the anterior denticle almost as distinct and large as the posterior denticle. Another 

 anterior tooth (fig. 5), with the crown more inclined and the anterior denticle less 

 marked, is interesting as showing the small and partially bifid root. A third 

 high-crowned tooth (fig. 6) is broader, and exhibits well the peculiar curvature of 

 the anterior and posterior borders ; its root is imperfect below. The inner vicav 

 of a tooth from a position further back in the jaw (fig. 7) displays the slight cleft 

 in the root above its bifurcation. Two still broader teeth are shown from the 

 outer and inner aspects respectively in figs. 8, 9. 



Teeth of this form are regarded as generically distinct from Corax by Priem 

 (1897) and Leriche (1902), who describe them as the type of a previously 



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