74 KANSAS UNIVERSITY SCIENCE BULLETIN. 



ectopterygoid (pterygoid) robust, with a single-spaced series of large, 

 slender teeth, gradually diminishing in size backwards; no teeth barbed. 

 Operculum strengthened on the inner side by a ridge extending horizon- 

 tally backwards from the point of suspension; branchiostegal rays about 

 twelve to sixteen in number. Vertebrae forty to fifty in number, about 

 half being caudal ; the centra at least as long as deep, constricted mesially, 

 and marked with small, irregular, longitudinal ridges. All except the 

 foremost rays of each fin finely divided distally, but none excessively 

 elongated. No post-clavicular plate. Pectoral fins large, pelvic fins much 

 smaller and arising far forwards; dorsal and anal fins large, neither 

 much longer than deep, the foi-mer arising much in advance of the middle 

 point of the trunk, the latter also far forwards; a posterior adipose dorsal 

 fin observed in a few well-presei-ved specimens; caudal fin forked, with 

 curved fulcral rays and stout, articulated, undivided rays at its base 

 both above and below. Rudimentary dermal scutes, not overlapping, in a 

 single median series between the occiput and the dorsal fin, and along the 

 course of the lateral line; a pair of enlarged hook-shaped dennal scutes 

 at the base of the tail, one on either side of the caudal pedicle. 



Doctor Woodward states that the cranial osteology of 

 Enchodus is best known from the specimens occurring in the 

 Engli.sh and Dutch chalk, and the trunk and fins are only sat- 

 isfactorily shown in the nearly complete fishes obtained from 

 the Upper Cretaceous of Westphalia and Mount Lebanon. 

 Fortunately the University of Kansas now has several very 

 complete skulls as well as other parts of the skeleton of 

 Enchodus, and we are thus enabled to add our quota to the 

 knowledge of the genus. 



The specimens in this collection are at variance with Wood- 

 ward's description regarding the following characters: 



Cranial roof flat, except for the grooved ridges on the 

 lateral margins and in the occipital regions; not all of the 

 species possess a series of minute teeth on the external alve- 

 olar border of the dentary ; maxillary never toothed ; teeth on 

 the pterygoid not always slender, but often quite stout, as in 

 E. petrosus; the diminution of the teeth on the pterygoid, 

 caudad, not always gradual, but often the second, third, or 

 even fourth tooth from the cephalic end may be the largest, 

 and the others irregular in size. This irregularity is obsen^- 

 able mostly in old individuals. In the young specimens and 

 in the smaller species, as E. shumardi, the large teeth of the 

 dentary and the pterygoid diminish in size caudad until they 

 disappear, and usually stand equidistant. The skulls repre- 

 sented in this museum are approximately triangular from a 

 lateral view, the length of the skull being slightly greater 



