A New Genus of Fishes from the Niobrara 



Cretaeeous. 



Contribution from the Paleontolo2:ical Laboratory, No. 46. 



BY S. W. WILI.ISTON. 



With Plate XXVI. 



Leptecodon rectus, gen. et. sp. nov. 



Slender and elongate; head elongate, the jaws slender, the an- 

 terior extremity in the specimen wanting. The hind end of the 

 mandibles is represented by an impression situated below the pos- 

 terior end of the skull. Teeth numerous, small, pointed, slender. 

 The orbit is situated posteriorly, is of moderate size and round. 

 Scapular arch strong, the large opercular space in front showing in- 

 dications of the thin opercular bones. Vertebrae about forty-five in 

 number, elongate, more than three times as long as deep, 

 much constricted in the middle. Pectoral fins small, composed of 

 seven or eight rays. Ventral fin very small, situated about the mid- 

 dle of the vertebral column; caudal fin small, the rays feeble, evi- 

 dently cartilaginous, the outline indicated on the stone; the shape of 

 the fin is regular apparently, the angles produced. Other fins 

 wanting or not preserved. The side of the body, as preserved, 

 shows three longitudinal rows of large, firmly united scutes, ap- 

 parently of the same number in each series as the vertebrae. The 

 scutes are in the form of a double trapezium, with the V posterior, 

 the middle raised into a well-marked carina, which runs from the 

 head to the tail. Apparently there are five rows of these scutes on 

 the body. At the front the topmost row is near the middle line, the 

 lateral row has its lower edge over the line of tlie vertebrcE, while 

 the lowest row has the carina just below the pectoral fin. The 

 scutes have a finely roughened appearance, due to minute, rounded 

 and shallow pits. There are no indications of small scutes on the 

 body intermediate between the larger ones. 



(113) KAN. rNIV. QUAR., VOIi. VIII, NO. 3, JULY, 1899, SERIES A. 



