DOS INDEX GENERUM MAMMALIUM. 
Perieromys (Croizer MS.) BraiNviLLE, 1840. Glires, Theridomyid:e. 
Comptes Rendus, Paris, X, No. 24, p. 929, Jan.-June, 1840 (nomen nudum?). 
Perriemys LAvRILLARD, Dict. Univ. Hist. Nat., XI, 206, 1848 (misprint). 
Perrieromys 'TRovEssART, Cat. Mamm. Viv. et Foss., Rodentia, 166, 1881 (syn- 
onym of Theridomys). 
Type not given. The name is applied to a genus of fossils from Mount Périer, 
France, in Croizet's manuscript catalogue, which is quoted by Blainville. 
Extinct. 
Perieromys: Mount Périer, France, the type locality; 0s, mouse. 
Perigalea (see Paragalia). Marsupialia, Peramelid:e. 
Perimeles Lenz, 1831. Marsupialia, Peramelid:e. 
Qo 
Naturgesch. Siiugethiere, 158, 1831. 
Emendation of Perameles Geoffroy, 1804.‘ 
erameles ist falsch gebildet." (Lenz. ) 
Perimys AMEGHINO, 1887. Glires, Chinchillidee. 
Mum. Sist. Especies Mamif. Fós. Patagonia Austral, p. 12, Dec., 1887. 
Species: Perimys erutus Ameghino, and P. onustus Ameghino, from the lower 
Tertiary of southern Patagonia. 
Extinct. 
Perimys: wept, around, near; /¢0s, mouse. 
Periphragnis Rorn, 1899. Ungulata, Ancylopoda, Leontiniide. 
Revista Mus. La Plata, IX, 387-388, 1899; AmmcuHino, Sin. Geol.-Paleont., 
Segundo Censo Nac. Repub. Argentina, I, Supl., p. 12, July, 1899. 
Type: Periphragnis harmeri Roth, from the upper ‘Cretaceous’ of Lago Musters, 
Territory of Chubut, Patagonia. 
Extinct. Based on molar teeth. 
Periphragnis: wepippay os, a fencing round. 
Periptychus Corr, 1881. Ungulata, Amblypoda, Periptychide. 
Am. Naturalist, X V, for Apr., 1881, 337, Mar. 25, 1881; Palzeont. Bull., No. 33, p. 
484, 1881; Proc. Am. Philos. Soc., XIX, 484, 1881; Tert. Vert., 387-405, 1885. 
Pteryptichus Corr, Proc. Am. Philos. Soc., X X, 509, Jan. 22, 1883 (misprint). 
Type: Periptychus carinidens Cope, from the Eocene of New Mexico. - 
** He [Marsh] states that the name of the Puerco genus Periptychus Cope is * pre- 
occupied,’ but does not point out how or where. Scudder’s Index shows that 
a division (not a genus) of Lepidoptera [ Vermes] has been called Periptyches, 
which is not preoceupation." (Corr, Am. Nat., XXVIII, 868, Oct., 1894.) The 
Zoological Record, however, gives Periptyches Grube, 1873, as a genus of Vermes. 
Extinct. 
Periptychus: mepi, around; zrvy», fold—probably in allusion to the molars, in 
which ‘‘the sides of all the cusps are marked with distinct, well separated, 
vertical ridges." 
Pernatherium Gervais, 1876. Ungulata, Ancylopoda, Chalicotheriid:e. 
Journ. de Zool., V, No. 6, pp. 425-432, pl. xvii, 1876. 
Pervatherium Newron, Geol. Record, for 1876, 256, 1878; Bonney, ibid., for 1877, 
296, 1880 (misprint). 
Type: Pernatherium rugosum Gervais, from the Eocene beds of Saint-Ouen, near 
Paris, France. 
Extinct. Based on a nearly complete caleaneum, the superior part of a meta- 
tarsal, or metacarpal, etc. 
Pernatherium: wépva, ham, femur; 97ptiov, wild beast. ‘‘Je donnerai à ce genre 
le nom de Pernatherium, qui rappelle la partie de son squelette qui nous met 
le mieux sur la voie de ses affinités." (GERVAIS. ) 
Perodicticus BENNETT, 1831. Primates, Lemuride. 
Proe. Zool. Soc. London, No. rx, Sept. 1, 1831, 109-110; Philos. Mag., new ser., 
X, 389, 1831. 
