176 KANSAS UNIVERSITY QUARTERLY. 



Sagenodus fossatus Cope, ib., 53 (Ctenodus). Permian, eastern Illinois. 



Dental plate 22 mm. in length; five crests present; crests coarsely 

 dentate, with three or four teeth in each, the grooves between them 

 marked by coarse, transverse, undulating grooves. 



Sagenodus gurleianus Cope, ib., 54 (Ctenodus). Permian, eastern Illinois. 



Number of ridges of dental plate uncertain, but probably not more 

 than four; crests sharp, elevated, and coarsely dentate. 



Sagenodus periprion Cope, ib., 527 [Ctenodus). Permian, Texas. 



Length of dental plate, 47 mm ; seven ridges present, their crests 

 perfectly smooth and uniform. 



Sagenodus porrectus Cope, ib., 527 [Ctenodus). Permian, Texas. 



Length of dental plate, 38 mm.; crests six in number, each with 

 four or five dentiform processes. 



Sagenodus dialophus Cope, ib., 526 [Ctenodus). Permian, Texas. 



Length of dental plate. 33 mm.; crests ten in number, with two or 

 three other rudimental ones posteriorly; crests entire, except at the 

 obliquely truncate distal extremity, where there are from two to four 

 dentations. 



Sagenodus pusiUus Cope, ib., 101 [Ctenodus). Permian, Texas. 



Length of dental plate, 7 mm. ; crests four in number, each with 

 two or three denticles, which are rectangular and little elevated. 



Sagenodus vabasensis Cope, Proc. Acad .Nat. Sci. Phil., 1883, 110 [Ctenodus); 

 Trans. Amer. Phil. Soc, xvi, 1886, 102 (id.) Permian, eastern Illinois. 



Length of dental plate to marginal base of second crest, 24 mm, ; 

 six crests present ; crests serrate nearly to their base, but the teeth 

 are obsolete on their basal halves. 



Sagenodus heferoloplnis Cope, Proc. Acad. Nat. Sci. Phil., 1883, 109 [Cteno- 

 dus). Permian, eastern Illinois. 



Dental plate apparently with but three crests. 



Sagenodus vinslovi Cope, ib., 1875, 410 [Ceratodus): Proc. Amer. Phil. Soc, 

 xvii, 1879, 102 [Ptyonodus). Permian, eastern Illinois. 



Coronal surface smooth, without irregularities or serrations ; inner 

 border with six notches. 



Sagenodus serratus Newberry, Rep. Geol. Surv. Ohio, ii, 59 [Ctenodus); Pale- 

 ozoic Fishes North Amer., 226, pi. xxxvii, f. 31 (id.) Coal Measures, east- 

 ern Illinois. 



Dental plate 32 mm. in length, with eight sharp, radiating ridges, 

 which terminate above in numerous, compressed, acute denticles, the 

 furrows between the ridges being pitted to'receive corresponding den- 

 ticles of the opposite teeth. 



