56 



FOSSIL FISHES OF THE ENGLISH CHALK. 



very narroAV and deep ; opercnhim strengthened on tlie inner side l)y a ridge 

 extending horizontally ])ackwards from the point of suspension ; branchiostegal 

 rays about 12 to 16 in nnniljer. Vertebrse 40 to 50 in number, about half 

 being caudal ; the centra at least as long as deep, constricted mesially, and 

 marked with small irregular longitudinal ridges. All except the foremost rays of 

 each fin finely divided distally, but none excessively elongated. No 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 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 series between the occiput and the dorsal fin, and along the course 



Fig. 12. Eurypholis hoissieri, Pictet; restoration (omiUing' external ornament), about three quarters 

 nat. size. — Upper Cretaceous ; Hakel, Mt. Lebanon, ag., angiilar; co., circumorbitals ; d., dentary ; 

 d.s., dorsal scutes ; ma;., maxilla ; op., operculum ; orh., orbit ; pel., postclavicular plate (obscuring 

 the pectoral arch to wliich the basals of the fin are attached) ; pL, pelvic fin-support; pmx., pre- 

 maxilla (with large teeth of palatine and ectopterygoid showing within) ; pop., preoperculum ; 

 so., suborbitals ; sop., suboperculum ; lateral line traversing row of scutes above vertebral column. 

 (From ' Catal. Foss. Fishes B. M.,' pt. iv, 1901.) 



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. 



Tyjje Siiecies. — Enchodns lewesiensis, from the English Chalk. 



Bemarhs. — Complete skeletons of species of this genus are known only from the 

 Upper Cretaceous of the Lebanon and Westphalia, perhaps also from the 

 Cretaceous of Comen, Istria. The remains from the English Chalk are compara- 

 tively fragmentary, but important as exhibiting the osteology of the head. The 

 general appearance of the fish would closely resemble that of EuryplioUs (Text- 

 fig. 12), which differs from Enchodus in the relatively large size of its pelvic fins, 

 the possession of a largo postclavicular plate, and the somewhat greater develop- 

 ment of its dermal scutes. 



