71 FOSSIL FISHES OF THE ENGLISH CHALK. 



fossils are known from the Turonian of Bohemia (Lepidenteron longissimum, A. 

 Fritsch, ' Rept. u. Fische bohm. Kreideform.,' 1878, p. 19, fig. 45). 



Horizons and Localities. — Probably Turonian zones: neighbourhood of Lewes, 

 Sussex ; Cuxton, Kent. Zone of Micraster coranguinum : Charlton, Bromley, and 

 Dover, Kent. Undetermined Senonian zones : Brighton ; Norwich. 



Family Halosaukid^e. 



A Cretaceous genus, Echidnocephalus, from the Senonian of Westphalia, is 

 essentially identical with the existing Halosaurus (Text-fig. 17). 1 An allied 

 extinct genus, Enchelurus, is also widely distributed in the Chalk. 



Genus ENCHELURUS, W. von der Marck. 



Enchelurus, W. von der Marck, Palaeontogr., vol. xi, 1863, p. 58. 



Generic Characters. — Vertebras very short and numerous, marked with delicate 

 longitudinal striaa ; neural arches in the abdominal region expanded into narrow 

 laminas. Paired fins small, about equal in size ; dorsal fin at least as deep as long, 

 arising opposite to or behind the pelvic fins ; anal fin much extended ; a separate 

 fringing caudal fin, pointed behind. Scales small, those of the lateral line 

 apparently thickened but not enlarged. 



Type Species. — Enchelurus villosus (W. von der Marck, loc. cit., p. 58, pi. ix, 

 fig. 5, and A. S. Woodward, Catal. Foss. Fishes B. M., pt. iv, 1901, p. 165), from 

 the Senonian of Westphalia. 



Remarks. — This genus differs from Halosaurus in the separation of the anal 

 from the caudal fin, which surrounds the pointed end of the body. It is best 

 known by a species from the Upper Cretaceous of Sahel Alma, Mount Lebanon 

 ( ilnrln-lurus sijriacus, A. S. Woodward, Catal. Foss. Fishes B. M., pt. iv, 1901, p. 1G5, 

 pi. xii, figs. 1, 2). 



1- Enchelurus anglicus, A. S. Woodward. Plate XV, fig. 3; Text-figure 18. 

 1001. Enchelurus anglicus, A. S. Woodward, Catal. Foss. Fishes B. M., pt. iv, p. 167, pi. xii, fig. 3. 



Type.— [mperfecl fish from one of the Cenomanian zones; British Museum. 



Specific Characters. — An imperfectly known species probably attaining a length 

 of aboul 2*5 cm. Operculum as deep as broad, gently rounded and not crimped 

 ;it the hinder border. 



1 A S. Woodward, "On Echidnocephalus, a. Ealosauroid Pish from the Upper Cretaceous 

 Formation of Westphalia," Proc, Zool. Soc, 1897, pp. 268 271, pi. xviii. 



