CESTKACIONTIDJE. 
255 
P. 2788. Tooth associated with fragment of cephalic dermal spine 
(Sphenonchus) ; Axmouth. Enniskillen Coll. 
P. 2193 a. Tooth; Aust Cliff, near Bristol. Egerton Coll. 
P. 5338. Seven teeth detached from matrix; Aust Cliff. 
P. 2787. Fragment of Aust bone-bed, with two large teeth, a small 
broken cephalic spine, and a fragment of the dorsal spine. 
Enniskillen Coll. 
19692. Anterior tooth; "Wurtemberg. Purchased, 1845. 
Of the following dorsal fin-spines, the majority doubtless pertain 
to Hybodus minor , but some almost certainly to Acrodus minimus :— 
P. 3169. Incomplete slender spine; Aust Cliff. Enniskillen Coll. 
P. 2176. Imperfect dorsal spines; Aust Cliff. Egerton Coll. 
34986. Two portions of dorsal spines, showing posterior denticles; 
Aust Cliff. Purchased, 1860. 
41293. Abraded dorsal spine; Aust Cliff. Purchased , 1869. 
24840. Two much broken dorsal spines ; Aust Cliff. 
Purchased , 1850. 
P. 430. Imperfect dorsal spine; Axminster. Purchased, 1882. 
Hybodus lawsoni, Duff. 
1842. Hybodus lawsoni, P. Duff, Geol. Moray, pp. 61, 63, pi. iv. figs. 1, 
2,5,6. 
(P) 1842. Tooth of Sphenonchus, P. Duff', op. cit. p. 63, pi. iv. fig. 11. 
1843. Hybodus dubius, L. Agassiz, Poiss. Foss. vol. iii. p. 188, pi. xxii. a. 
figs. 8—10. ^ 
(P) 1843. Sphenonchus martini, L. Agassiz, to?n. cit. p. 203, pi. xxii. a. 
figs. 15-17. 
Type. Dorsal fin-spines and teeth. 
A small species. Teeth with a high crown, the principal cone 
long, slender, and pointed, and at least one well-separated lateral 
cone on each side ; coronal surface strongly wrinkled. Base of 
tooth slightly expanded posteriorly. 
Form. Sf Loc. Bhaetic : Linksfield, near Elgin, Scotland 1 . 
P. 2174. Two teeth. Egerton Coll. 
P. 2174 a. A small, abraded dorsal spine, and fragment of a larger 
specimen. Egerton Coll. 
1 A tooth from the Wealden of Hanover is referred to H. dubius, Agass., by 
C. Struckmann, Wealden-Bild. Umgegend Hannover, 1880, p. 92, pi. iii. fig. 10. 
