227 



prcmaxillar}' toctli from tlic outer row. The external lamina of the premax- 

 illary forms an extensive squamosal suture with this part of the maxillary by 

 overlapping it from above. This arrangement shows a certain similarity to 

 Esox, especially in the large number of palatine and small number of max- 

 illary teeth. It (lillcrs materially in the lack of articular surfaces between 

 the maxillary, palatine, etc., in the upward prolongation of the prcmaxillary, 

 and the peculiar forms of the teeth. 



Stkatodus apicalis, Cope. 



Established on one incomplete individual, as above mentioned. 



The maxillary teeth are mostly smaller than the premaxillaries, and 

 diminish in size posteriorly ; there are four or five series of them anteriorly ; 

 seven to nine rows on the palatine bones; they are slender, and curved down- 

 ward from oblicpic bases, and cylindric in section ; they contract to a neck, 

 and then expand into the ovate spade-shaped cutting apex. They are in every 

 respect the largest of the teeth, some reaching a half-incli in length. Those 

 on Ihc inferior or outer margin are most slender; those of the inner stouter 

 and more conic. All the spade-like apices are black in the specimen, while 

 the shanks are i)ale, except the premaxillaries. The palatine bones are flat- 

 tened in one plane, and contracted at both ends. At the anterior, there is an 

 external concavity, perhaps Ibr niaxillary or prcmaxillary. A ridge divides 

 the upper surface lengthwise ; the outer edge is thinned posteriorly, and there 

 are three long grooves which extend to the posterior extremity, probably for 

 sutural union with the pterygoid. The premuzillary bears a slight resem- 

 blance to the mandibular bone of a chimeroid turned upside down. 



Measurements. 



u. 



Length of a portion of .in os palatinmn i^-_z-- ^- ^^ 



Length of same restorcii 0. 148 



Greatest %vi(lth 0.020 



Greatest thickness on tlie margin 0. 003 



Longth of the premaxiHary (fr.agment) 0.013 



Length of the prcinaxiUary, inner side 0. 025 



Length of the prcmaxilhiry, outer sido to the maxillary 0. 012 



Width of the prcmaxillary in front above 0. 010 



Length of a preniaxillary tooth 0.005 



This fish was considerably larger than Esox reticulatus or E. Indus. In 

 the lack of mandible, its habits cannot be fully inferred; but the armature of 

 the superior bones of the mouth is less powerful, relatively, than in those 

 fishes. 



Found l)v nivsclf in the blue limestone near Fort Wallace. 



