78 



FOSSTL FISHES OF THE ENGLISH CHALK. 



1. Ctenothrissa radians (Agassiz). Plate XVII; Plate XVIII, figs. 1 — 5; Text- 

 figure 20. 



1835-38. Beryx radians, L. Agassiz, Poiss. Foss., Feuill., p. 55, and vol. iv, pp. 4, 118, pi. xiv b, fig. 7 ; 



pi. xiv c, figs. 7 — 9. 

 1888. Beryx radians, A. S. Woodward, Proc. Geol. Assoc, vol. x, p. 326, pi. i, fig. 9. 

 1899. Ctenothrissa radians, A. S. Woodward, Aim. Wag. Nat. Hist. [7], vol. iii, p. 491. 

 1901. Ctenothrissa radians, A. S.Woodward, Catal. Foss. Fishes B. M.,pt. iv, p. 122, pi. x, figs. 1 — 4. 



Type. — Imperfect fish from one of the Turonian zones; British Museum. 

 Specific Characters. — A robust species attaining a length of about 25 cm. 



Fig. 20. Ctenothrissa radians (Agassiz) ; restoration, about two-thirds nat. size. — English Chalk. 



Length of head with opercular apparatus somewhat less than the maximum depth 

 of the trunk and contained about twice in the length from the pectoral arch to the 

 base of the caudal fill. Head and opercular apparatus with a fine rugose ornament ; 

 fche supramaxill 33 remarkably short and deep; operculum about twice as deep as 

 broad, not covered with scales, except perhaps in its antero-superior portion. 

 Vertebrae approximately 40 in number. Pelvic fins with 7 or 8 stout rays, which, 

 \\ Inn ad pressed to the trunk, extend to the anal fin ; dorsal fin with 20 to 25 rays, 

 arising just in front of a point opposite the insertion of the pelvic fins; anal 

 tin, with at least 12 rays, arising opposite the hinder end of the dorsal fin. 

 Scales moderately largo; lateral line extending along the ninth series above that 



