30 FOSSIL FISHES OF THE ENGLISH CHALK. 



orbit in tlie fossil is evidently reduced by crushing, and the remains of the jaws 

 are somewhat displaced ; but the suspensorium must have been inclined a little 

 forwards, with the articulation for the mandible beneath the middle of the eye. 

 The jaws, so far as preserved, resemble those of Hophpteryx, with the same con- 

 spicuously ornamented supramaxilla {smx. 2). The preoperculum (pop-) also 

 resembles that of Hoploj)tery,v, with rounded angle and strongly pectinated hinder 

 border. The well-preserved operculum (op.) shows traces of scales covering its 

 antero-superior edge, but the greater part of it is exposed and ornamented with 

 strong, short, rounded ridges, which are directed backwards. Two larger ridges 

 beneath these extend from the point of suspension of the operculum to its great 

 flattened posterior spine. The sul)operculum (sop.) is relatively small, with ridged 

 ornament directed downwards and backwards ; while the interoperculum, exposed 

 on the right side of the fossil, is large and similarly ornamented. The deep 

 ceratohyal, shaped like that of Hoplopteryx, bears some large branchiostegal rays. 

 The expanded upper lamina of the clavicle {d.) and the scales are very strongly 

 pectinated. The pectoral fin-rays (pet.) must have been delicate. 



Horizon and Locality. — The matrix of the type and only known specimen in the 

 Bowerbank Collection much resembles the marly chalk of the zone of Holaster 

 suhglohosHs. It is labelled as having been obtained from Bromley, Kent. 



Snhorder ABODES. 



Fdiii ily MUE iENID.E . 



Germs URENCHELYS, A. S. Woodward. 

 Urenchelys, A. S. Woodward, Ann. Mag. Nat. Hist, [7], vol. v, 1900, p. 322. 



Generic Gharacters. — Teeth small, l)luntly conical, and arranged in numerous 

 series. Slender branchiostegal rays not curving round the opercular apparatus. 

 Vertebrae somewhat exceeding 100 in number, the hindermost bearing a pair of 

 expanded hypural bones. Bectoral fins present ; dorsal fin arising immediately 

 behind the occiput and extending to the caudal fin, which has stouter rays and is 

 very small but separate. Scales rudimentary. 



Type tipecies. — llreurliclys avus, from the LTpper Cretaceous of Saliel Alma, 

 Mount Lebanon. 



Remarks. — This genus is interesting as comprising the oldest known eels, which 

 differ from all the Tertiary and existing eels in still retaining the caudal fin. 

 Nearly complete specimens of two species have been obtained from the Upper 

 Cretaceous of Mount Lel^anon ;' but only imperfect skulls have hitherto been dis- 



1 Urenehelys avus and U. hahelensis, A. S. Woodward, Catal. Foss. Fishes B. M., pt. iv, 1901, 

 pp. 337—339, pi. xviii, figs. 1—3. 



