ENCHODONTID.E. 
191 
thickened and tumid, with only one large tooth fixed at its anterior 
end ; ectopterygoid robust, with a single spaced series of large 
slender teeth, gradually diminishing in size backwards ; no teeth 
barbed. Operculum strengthened on the inner side by a ridge 
extending horizontally backwards from the point of suspension ; 
branchiostegul rays about 12 to 16 in number. Vertebra) 40 to 50 
in number, about half being caudal ; the centra at least as long as 
deep, constricted mesially, and marked with small irregular longi- 
tudinal ridges. All except the foremost rays of each fin finely 
divided distally, but none excessively elongated. No postclavieular 
plate. Pectoral fins large, pelvic fins much smaller and arising far 
forwards ; dorsal and anal fins large, neither much longer than 
deep, the former arising much in advance of the middle point ot 
the trunk, the latter also far forwards ; [a posterior adipose dorsal 
fin observed in a few well-preserved specimens ;] caudal fin forked, 
with curved fulcral rays and stout, articulated, undivided rays at 
its base both above and below. Rudimentary dermal scutes, not 
overlapping, in a single median scries between the occiput and the 
dorsal fin, and along the course of the lateral line ; a pair of 
enlarged hook-shaped dermal scutes at the base of tho tail, one on 
either side of the caudal pedicle. 
The cranial osteology of Enchodns is best known from the 
specimens occurring in the English and Dutch Chalk ; the trunk 
and fins are only satisfactorily shown in the nearly complete fishes 
obtained from the Upper Cretaceous of Westphalia and Mount 
•Lebanon. 
Enehodus lewesiensis (Mantell). 
[Plate XI. fig. 1.] 
1822. Esox lewesiensis , G. A. Mantell, Foss. South Downs, p. 25/, 
pi. xxv. fig. 13, pi. xxxiii. figs. 2-4, pi. xli. figs. 1, 2. 
1835-44. Enehodus hulocycm, D. Agassiz, Poiss. Ross., Feuill. p. 55, 
and vol. v. pt. i. p. 64, pi. xxv c. figs. 1-16. 
1850. Enehodus halocycn, F. Dixon, Geol. Sussex, p. 373, pi. xxx. 
figs. 20, 27, pi. xxxi. fig. 11. 
(?) 1875, Enehodus halocyon, II. B. Geinitz, Palseontogr. vol. xx. pt. ii. 
p. 226, pi. xli. figs. 5-20 (in part). 
1888. Enehodus levesiensis , A. S. Woodward, Proc. Geol. Assoc, vol. x. 
p. 315 (in part), pi. i. fig. 6 ( non fig. 6). 
7' ype. Fragment s of jaws, &c. ; British Museum. 
The type species, known only by fragmentary specimens, usually 
small, but the mandible sometimes attaining a length of 0’1. The 
sides of the cranial roof and the outer face of the mandiblo 
ornamented with numerous and closely-arranged sharp ridges, 
