1903.] Hay, North American Cretaceous Fishes. J I 



bases, and that sufficient time had not elapsed for the scars 

 to be wholly healed. In front of and above the base of the 

 supposed former fang, on the anterior extremity of the pala- 

 tine, there is a process of bone which may be regarded as an 

 outgrowth preparatory to the attachment of a new fang. It 

 is rather thin from side to side, only about one half as thick 

 as would be required for the fang, but it is possible that its 

 thickness might become greater in due time. Whether or 

 not a new fang could be produced and effect an attachment 

 without the support and protection of a fang already in place 

 seems to be doubtful. It seems likely that every victim by 

 its strugglings would destroy any incipient connections that 

 had been formed. , 



Fig. 51 represents a damaged dentary bone of this species, 

 with two teeth nearly complete. The most anterior of these 

 is shown two-thirds of the 

 natural size, in order to 

 display the rather strongly 

 developed ridges on the pos- 

 terior half of the tooth. On 

 the lingual face of the tooth 

 these ridges are found well Fig. 51. Enchodus petro^^us Co^^. No. 2062. 



forward, but here they are Dentary, X i ; one tooth, x i 



rather short. Toward the hinder border 6i this face they rise 

 well toward the tip of the tooth. About three millimeters 

 above the base of the tooth the ridges cease suddenly, and 

 the portion of the surface below them is provided with very 

 fine striations. The anterior fang is broken away, but its 

 outlines are restored from another specimen. The number 

 is 2062. 



The surfaces by means of which the palatine bone comes 

 into contact with the bone which acted as its suspensory, 

 doubtless the prefrontal, deserve description. These articu- 

 latory surfaces are found at the hinder end of the palatine, 

 and those of Cope's type are shown in Fig. 62; those of E. 

 scsvus in Fig. 61. In the former we have two processes, one 

 below and directed upward and outward. The posterior face 

 of this is smooth and forms one of the articulatory surfaces. 



