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The right vomerine tooth of a large species of Edaphodon, from 

 the Cretaceous of Columbus, Mississippi, now in the Museum of the 

 Academy of Natural Sciences, Philadelphia, is described as the 

 mandibular tooth of a distinct genus and species, Eumylodus 

 laqueatus, J. Leidy, Ext. Vert. Fauna W. Territ. (Rep. U.S. Geol. 

 Surv. Territ. vol. i. 1873), p. 309, pi. xix. figs. 21, 22, pi. xxxvii. 

 figs. 13, 14. 



The genus Diphrissa, E. D. Cope (Vert. Cret. Form. West, 1875, 

 p. 283), is founded upon a mandibular tooth differing only from that 

 of the typical Edaphodon in the presence of a single outer tritor — a 

 feature noted above in Edaphodon reedi. Two species are recognized 

 from the Cretaceous Greensand of New Jersey, the type being 

 D. solidula, previously named Ischyodus solidulus (E. D. Cope, Proc. 

 Amer. Phil. Soc. vol. xi. 1869, p. 244). The description of the 

 second species, D. latidens, Cope, accompanies the generic diagnosis ; 

 and both of the type specimens are in the Cope Collection, Phila- 

 delphia. 



The following genera and species appear to the present writer to 

 be probably founded upon indeterminable fragments of the teeth of 

 Edaphodon. They were obtained from the Cretaceous Greensand 

 of New Jersey, and are preserved in the Cope Collection : — 



Bryactinus amorphus,~E. D. Cope, Vert. Cret. Form. West (1875), 



p. 282. 

 Isotcenia neoccesariensis, E. D. Cope, ibid. p. 293. 



The following genus and species is founded upon a palatine and 

 vomerine tooth, of which the former appears to be a broken Edapho- 

 dont tooth : — 



Mylognaihus priscus, J. Leidy, Proc. Acad. Nat. Sci. Philad. 

 1856, p. 312, and Trans. Amer. Phil. Soc. [2] vol. xi. 

 (1859), p. 153, pi. xi. figs. 24-30.— Tertiary Lignite; 

 Nebraska. 



The following genus, with three species, is founded upon an 

 imperfect mandibular tooth showing only an inner tritor. A palatine 

 tooth having long, narrow, outer and inner tritors, is doubtfully 

 associated with this : — 



Leptomylus densus, E. D. Cope, Proc. Boston Soc. Nat. Hist, 

 vol. xii. (1869), p. 313.—Greensand ; New Jersey. [The 

 type species ; E. D. Cope Collection, Philadelphia.] 



