Benedenius deneensis, Traquair. 447 



which may be due to its extremity being imbedded in the 

 matrix. 



On the evidence of the material now available it appears 

 that the depth of the body is contained 2 to 2f in the total 

 length (without caudal fin), the length of the head 4 to 4^^. 

 The caudal peduncle is much deeper tlian long and the length 

 of the caudal fin is contained about 4 times in the total. 



The following measurements are taken from specimen A:— 



millim. 



Total length •• ^90 



Length of head '^^ 



From head to caudal fin I'O 



Caudal fin (end imperfect) 76 



Greatest depth of body 100 



Length of caudal peduncle 22 



Depth of caudal peduncle _. . . 31 



From head to dorsal fin (in a straight 



line) 102 



From head to ventral fin 79 



From head to anal fin 125 



Length of dorsal fin 58 



Greatest depth of dorsal fin 40 



Length of anal fin 25 



Greatest depth of anal fin 40 



Length of pectoral fin 46 



The dorsal fin, high and pointed in front, low behind, 

 formed of 54 slender, distally bifurcating rays, originates 

 iust behind the vertical of the base of the ventrals and twice 

 as far from the base of the caudal as from the end of the 

 snout. Van Beneden says, " S'il y a des ^cailles sur le bord 

 ant^rieur, elles doivent Stre extifemement petites." Traquair, 

 notwithstanding the imperfect condition of the fossil, recog- 

 nized the presence of fulcra, but could not have given a quite 

 exact representation of them, nor are they correctly shown m 

 Fraipont's figure. There is a series of well-developed fulcra 

 along the anterior border of the fin, as much developed as in 

 Eurynotus, and these fulcra are a prolongation of the enlarged 

 dorsal scales or ridge-scutes, which extend both in front and 

 behind the dorsal, not to midway between the fin and the 

 head but right to the occiput. The posterior half of the base 

 of the dorsal fin happens to be denuded of scales in specimen 

 A and shows well the distal endoskeletal fin- supports (baseosts) 

 as' short stout bones, somewhat hourglass-shaped, one to every 



three vays. ^ , ^ i , r j f on 



Fraipont represents the dorsal fin as short, ormed ot Zb 



rays ancl ending above the origin of the anal. 1 his condition 



