24- KANSAS UNIVERSITY QUARTERLY. 



Platygonus compressus Leconte, Amor. Journ. Sci. (,2), v, lOo, .l;in., ISJS: 



Mem. Amer. Acad., New Ser. iii, 259-274, pis. i-iv, 1848: Pruc. Acad. Nat. 



Sc. Phil. Jan. 1852, p. 4; I.eidy, Trans Amer. Phil. Soc. (2) x, 321-343, pis. 



35-38,18.52: Trans. Wagner Free Ins. ii, 41-50, pi. viii, f. 1; Cope. Proc. 



Am. Phil. Soc. 1885,15: Wortman, Rep.Ind. Geol. Surv. 1887. Euchoerm 



macrops Leidy, Trans Amer. Phil. Soc. (2), 340, pi. 35, 1852. ProtochwruH 



prisinaticus Leconte, Amer. Joiirn. Sc. (2). v, 105; Proc Acad. Nat. Sc vi, 



5: Leidy, Trans. Amer. Phil. Soc. x, 33!), 1852. 

 P. Ziegleri Marsh, Amer, Journ. Sci. ii, July, 1871, Grizzly Buttes, Wyo. 

 P. striatus Marsh, Amer. Journ. Sci. July, 1871. Pliocene, Nebr. 

 ? P. Oondoni Marsh, 1. c. Pliocene, Oregon. 

 P. vetus Leidy, Proc. Phil. Acad. Nat. Sc, 1882, p. 301. Penna. 



P. alemanni Duges, La Naturaleza, 1887, p. l(i. pi. i. ii. Mexico (Leidy, 



Trans. Wagner Free Ins. ii, p. 49). 

 P. bicalcaiatus Cope, Ann. Rep. Geol. Surv. Texas for 1892, pp. 68,09, pi. 



xiii, f. 5. Blanco Beds, Texas. 

 Of F. Zicglcri, the type specimen comprises the upper premolars 

 only, and the species is based upon "the remarkably strong basal ridge, 

 which on the inner border at least of the first and second premolars 

 exceeds in breadth that in Platygoiiiis coDiprcssus Leconte, although 

 on the posterior margin it is less well developed than in that species." 

 P. striatus is based upon yet more uncertain evidence, the second 

 left lower premolar. "The enamel is marked by delicate irregular 

 stripe, mostly parallel with the base of the crown," a character not 

 found in our specimens. 



P. Condoni is based upon the three upper molars and is doubtfully 

 referred to this genus by the author. The length of the last upper 

 molar precludes the probability of identity. 



P. vetus Leidy was based upon two jaw fragments with teeth. 

 "The jaw below the position of the first molar is thick and shal- 

 low; below the last tooth it abruptly deepens, and a short distance 

 back it is nearly double the depth. The upper teeth exhibit a well 

 produced basal ridge fore and aft, but none laterally, except the 

 feeble elements of it between the lobes of the crown." Measure- 

 ments will be found further on. 



P. hicalcai-atiis Cope is based upon the posterior part of a last 

 lower molar, and the base of the canines. The molar differs in 

 having not one, but two distinct cusps on the heel. 



A species from the Loup Fork Beds of Nebraska figured and 

 described by Scott in the Bulletin of Mus. Comp. Zool. xx, 76, and 

 referred to Dicotylcs without name, must rather belong in Platyi^oiuis 

 from the simpler structure of the premolar. 



The only species then with which our specimens can be compared 

 is the original, P. compressus Lee, which has been found in Virginia, 

 Kentucky, Pennsylvania, New York, Iowa and Missouri, so far as the 

 fragmentary specimens indicate. 



