EXCHODOXTID.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 ; 
branchiostegal rays about 12 to 1(3 in number. Vertebrae 40 to 50 
in number, about half being caudal; he 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. Xo postclavicular 
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 of 
the trunk, the latter also far forwards ; [a posterior adipose dorsal 
fill 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, nob 
overlapping, in a single median series 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 the tail, one on 
either side of the caudal pedicle. 
The cranial osteology of Encliodus 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. 
Enchodus lewesiensis (Mantell). 
[Plate XI. fig. 1.] 
1822. Esox lewesiensis, G. A. Mantell, Foss. South Downs, p. 237, 
pi. XXV. fig. 13, pi. xxxiii. figs. 2-4, pi. xli. figs. 1, 2. 
1835-44. Enchodus halocyon, L. Agassiz, Poiss. Foss., Feuill. p. 55, 
and vol. v. pt. i. p. 64, pi. xxv c. figs. 1-16. 
1850. Enchodus halocyon, F. Dixon, Geol. Sussex, p. 373, pi. xxx. 
figs. 20, 27, pi. xxxi. fig. 11. 
(?) 1875. Enchodus halocyon, H. B. Geinitz, Palmontogr. vol. xx. pt. ii. 
p. 226, pi. xli. figs. 5-20 (in part). 
1888. Enchodus levesiensis, A. S. Woodward, Proc. Geol. Assoc, vol. x. 
p. 315 (in part), pi. i. fig. 5 {non fig. 6). 
Type. Fragments 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 mandible 
ornamented with numerous and closely-arranged sharp ridges, 
