201 



der rod, and a shallow rabbet along the flat edge is occupied by a slender flat 

 rod. Of the four principal rods, the two median are the most slender, and 

 the flat marginal the widest. Of the two median, that next the latter is the 

 wider. The stout marginal, or probably anterior, rod is segmented en chev- 

 ron, the angle directed distally and lying near the free margin. The suture of 

 the resulting segments is entirely straight, except, when returning, it approaches 

 the margin, where it suddenly turns to the margin at right angles to it. The 

 next rod is segmented without chevron obliquely backward and inward ; 

 where it leaves and reaches the margins, it is at right angles to them, and the 

 margin projects obtusely at those points. Between the ends, the suture is very 

 irregular and jagged, sending processes forward and backward. The segmen- 

 tation of the next rod is similar, but more regularly serrate; distally, it becomes 

 as irregular as in the last. The transverse marginal termini of the sutures are 

 serrate in both. The inner and widest rod presents a still more regularly 

 serrate oblique suture with the truncate extremities; but, owing to the width 

 of the rod, the near approximation of the sutures continues for a longer 

 distance. When broken, the suture appears steplike. 



Measurements. 



M. 



Length of a Lagment of the (?) caudal spine 0.25 



Width of the fragment at the proximal fracture, 0.06 



Greatest thickness at the proximal fracture 0. 013 



Width of the posterior rod at the proximal fracture 0. 0245 



Length of six distal caudal verteh: oe 0. 10 



Width of the hajmal spine of the second of the series 0. 024 



Vertical diameter of the centrum of the first of the series 0. 025 



Length of the neural spine and centrum of the anterior caudal 0. 108 



Transverse diameter of the neural spine of the anterior caudal at the hase 0. 0235 



Antero-posterior diameter of the four anterior caudal neural spines in contact 0. 069 



Length of the centrum of a dorsal 0.04 



Vertical diameter of a dorsal 0. 0615 



Transverse diameter of a dorsal (crushed) 0. 041 



These remains were found in place by Prof. B. F. Mudge ; he states that 

 their extent was eight feet. As they embrace no cervical vertebra? nor por- 

 tions of cranium, two feet are probably to be added, giving a total of near ten 

 feet for the length of this fish. It was discovered at a point on the bank of 

 the Solomon or Nepaholla River, in Kansas, one hundred and sixty miles 

 from its point of junction with the Kansas River. 



PORTHEUS LESTEIO, Cope. 



Represented by a portion of the cranium, including both mandibular 



rami, and the maxillary and premaxillary bones of one side, all with dentition 

 26 c 



