Ordo IX. fTillodontia, Zittel, 1893. 
Tillodontia et Taerdodonta, Cope. 
Subordo I. Tiilodontia. 
1897. — J. L. Wortmann, Caracters of the Tillodontia, — Biill. Ara. Mus. 
Nat. Hist., TX, p. 61. 
Familia I. j Esthonycidae. 
761. fEsthonyx, Cope, 1874. 
4086. 1 bisulcatus, Cope, [Final] Ecport Ext. Vert. 
New-Mexico, Exp. West 100 Mcr., 1877, 
p. 1.54, pl. 40, lig. 27 — 33. 
4087. t acer, Cope, Ann. Kep. U. S. Geol. Surv., 
1874, p. 119. 
f Eocaen. 
Nov.-Mcxico. 
j Eocaen. 
Nov.-Mexico. 
4088. t Burmeisteri, Cope, Report Vert. Foss. 
New-Mexico, 1874, p. 7;- [Fiual] Ecport, 
1877, p. 156; Tert. Vert. '1884, p. 204, 
pl. 24 c, fig. 1 — 10. 
4089. f acutidens, Cope, Bull. Geol. Surv., 1881, 
p. 185; Tert.Vert., 1884, p. 210, pl, 24^ 
fig. 17—21. 
4090. tspatularius, Cope, Amer. Natur., 1880, 
p.908; Tert.Vert., 1884, p. 211, pl. 24^ 
fig. 22-2,5. 
f Eocaen. 
Nov.-Mexico. 
f Eocaen. Wyoming. 
f Eocaen. lAvoming. 
762. + Platychoerops, Charlesw., 1855. 
Mioiophus, Owen, 1865. 
4091.f Richardsoni, Charlesw., Eep. Erit. Ass. for f Eocaen. Europa, 
1854 (1855), p. 80. Insui. Britannia. 
planiceps, Owen, Geol. Mag., II, 1865, » 
p. 339, pl. X. 
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