Davis — On t}\e Fossil Fish of the Cretaceous Formations of Scandinavia, 383 



Family.— SCYLLIIDiE. 



Grenus. Scyllium. Cuvier. " Rfegne Animal," vol. ii., p. 124. 1817. 



First dorsal fin above or behind the pelvis ; origin of the anal always in 

 advance of that of the second dorsal ; upper edge of the caudal fin not serrated. 

 Teeth small, delicate, with a large middle cusp, and generally one or two 

 smaller lateral cusps ; arranged in numerous series. 



Scyllium planum^ Davis. 

 (PI. XXXVIII., fig. 9.) 



Teeth having the characteristics of this genus have been found in the 

 chalk-formation at Terkild-Skov in the Island of Seeland, and are comprised in 

 the collection of the Zoological Museum of the University of Copenhagen, 

 placed at my disposal by Prof. Dr. Liitken. They are small, and have probably 

 been derived from the posterior portion of the lower jaw, though two or three 

 teeth on each side the symphysis of the lower jaw are similar in form to the 

 posterior ones, and these specimens may have been so situated. They have a 

 breadth of O'OOS m. across the base of the crown. The principal median 

 cone is only equal in height to half the breadth of the tooth ; on each 

 side is a lateral cone smaller than the median one. Each of the cones is 

 rounded and somewhat thick at the base, tapering rapidly to a point with a 

 slight curvature laterally. They are smooth. The base of the crown has a 

 sygraoidal curvature. The root is short, and corresponds with the base in out- 

 line. Its outer surface slightly retreats from the base of the crown ; the inner 

 surface is expanded and bulbous. 



The teeth from the chalk of Seeland are very similar to some of the teeth 

 of the existing dogfish, Scyllium canicula, Cuv. Amongst fossil forms the nearest 

 relationship will probably be found with Scyllium {Thyellind) elongatum* Davis: 

 in this species, from the soft chalk of Sahel Alma in Mount Lebanon, the central 

 cusp is much longer than in these specimens ; and apart from the difference due 

 to the position in the mouth, the teeth have generally a more graceful and 



* Trans. Eoy. Dublin Society, N.S., vol. iii., p. 473, pi. xiv., figs. 2, 3. 



