MERIONES—MERYCODUS. 411 
. Meriones F. Cuvirr, 1823. Glires, Zapodid:e. 
Dents Mamm., 187-188, 256, 1823; G. Cuvier, Recherches Oss. Foss., nouv. éd., 
V, pt. r, 34, 1823; I. GEorrnov, Dict. Classique Hist. Nat., VII, 323, Feb., 1825. 
Type: Dipus americanus Barton, from the vicinity of Philadelphia, Pennsylvania. 
Name preoccupied by Meriones Illiger, 1811, based on two species of Gerbillin:e. 
Merychippus Leipy, 1857. Ungulata, Perissodactyla, Equide. 
Proc. Acad. Nat. Sci. Phila., for 1856, 311, 1857; Hay, Cat. Foss. Vert. N. Am., 
Bull. 179, U. S. Geol. Surv., 616-618, 1902. 
Type: Merychippus insignis Leidy, from the Miocene, Bijou Hills, South Dakota. 
Antedates Protohippus Leidy, 1858. 
Extinct. ‘‘ Founded upon a first and second molar of the upper jaw of a remark- 
able equine animal, in the structure of the teeth approximating the ruminant 
family." (Lerpy.) 
Merychippus: pve, unpvkos, ruminant; 7770s, horse. 
Merychyus Leipy, 1858. Ungulata, Artiodactyla, Agriochceride. 
Proc. Acad. Nat. Sci. Phila., 1858, 25-26; Hay, Cat. Foss. Vert. N. Am., Bull. 
179, U. S. Geol. Surv., 669, 1902 (type fixed). 
Species, 3: Merychyus elegans Leidy (type), M. medius Leidy, and M. major Leidy, 
from a Miocene deposit in the valley of the Niobrara River, Nebraska. 
Extinct. 
Merychyus: unpve, unpvkos, ruminant; vs, ds, pig. 
Merycochoerus Lripy, 1858. Ungulata, Artiodactyla, Agriochceride. 
Proc. Acad. Nat. Sci. Phila., 1858, 24-25; Hay, Cat. Foss. Vert. N. Am., Bull. 
179, U. S. Geol. Surv., 667-668, 1902. 
Type: Merycochoerus proprius Leidy, from the Miocene red-grit bed near Fort 
Laramie, Wyoming. 
Extinct. Based on ‘several halves of upper and lower jaws.’ 
Merycochoerus: u9pv&, unovios, ruminant; yozpos, hog. 
Merycodesmus Scort, 1898. Ungulata, Artiodactyla, Agriochcerid:e. 
Proc. Am. Philos. Soc., XX XVII, 75-77, Apr. 15, 1898 (sep., pp. 3-5). 
Type: Merycodesmus gracilis Scott, from the Eocene of the Uinta Basin, Utah. 
Extinct. 
Merycodesmus: unHpve, unpvkos, ruminant; 6¢640s, bond—in allusion to its rela- 
tionship with Leptomeryx and Protoceras. ‘The entire structure of Merycodesmus 
strongly suggests that it was the forerunner of the White River genus Lepto- 
meryx, and through a somewhat different line, of Protoceras also." — (Scorrm.) 
Merycodon (‘Letpy’) ManscHarL, 1873. Ungulata, Artiodactyla, Agriochceride. 
ManscHaLL, Nomenclator Zool., Mamm., 8, 1873. 
Misprint for Merycoidodon Leidy, 1848.  Merycodon does not occur in D. D. Owen's 
Rept. Geol. Surv., Wisconsin, as given by Marschall. 
Merycodon Mercerrat, 1891. Ungulata, Litopterna, Prototheriide. 
Revista Mus. La Plata, I, 450,466—467, 1890-91. 
Species: Merycodon damesi Mercerat, from Monte Leon; and M. rusticus Mercerat, 
from the Rio Santa Cruz—both from the Eocene of Patagonia. 
Name preoccupied by Merycodus Leidy, 1854. 
Extinct. 
Merycodon: u19)pv&, unpvkos, ruminant; dd@v=ddo0vs, tooth. 
Merycodus Lripy, 1854. Ungulata, Artiodactyla, Cervidze. 
Proc. Acad. Nat. Sci. Phila., 1854, No. riz, 90; Hay, Science, new ser., IX, 594, 
Apr. 21, 1899; Cat. Foss. Vert. N. Am., Bull. 179, U. S. Geol. Surv., 683, 1902. 
Type: Merycodus necatus Leidy, from the Pliocene of the Bijou Hills east of the 
Missouri River, South Dakota. 
Extinct. Based on ‘‘the fragment of a lower jaw, containing a last premolar 
and the first true molar." 
