490 INDEX GENERUM MAMMALIUM. 
Metriotherium Firnor, 1882. Ungulata, peda Anoplotheriidze. 
Mém. Soe. Sci. Phys. Nat., Toulouse, 99-103, pl. x, figs. 1-4, 1882. 
New name for Mn erum Filhol, 1880, which is preoccupied by Mesotherium 
Serres, 1857, a genus of Typotheria. 
Extinct. 
Metriotherium: uérpioc, moderate; 67ptov, wild beast. 
Miacis Corr, 1872. Creodonta, Uintacyonide. 
Palzeont. Bull., No. 3, p. 2, Aug. 7, 1872; Proc. Ec Philos. Soc., XII, for July-Dec., 
1872, 470, Jan., 1873. 
Type: Miacis parvivorus Cope, trom the Eocene of Blacks Fork of Green River, 
Wyoming. 
Extinct. Based on ‘‘a portion of the right ramus mandibuli, containing por- 
tions of three molars, the penultimate being perfect." 
Miacis: ueícov, less; dis, point. 
Mico (subgenus of Hapale) Lesson, 1840. Primates, Hapalide. 
Spócies Mamm.,. 184, 192-194, 1840; Nouv. Tableau Régne Anim., Mamm., 8, 
1842; RErcHENBACH, Vollstind. Naturgesch. Affen, 6, 1862 (raised to generic 
rank); Gray, Cat. Monkeys, Lemurs & Fruit-eating Bats Brit. Mus., 64, 1870. 
Type: Simia argentata Miller, from the banks of the Para and Amazon, Brazil. 
Mico: Native name, used on the Orinoco, signifying ‘guenon,’ or long-tailed 
monkey. (Bvurrow, Hist. Nat., XV, 121, 1767.) 
Micoella Gray, 1870. Primates, Hapalidee. 
Cat. Monkeys, Lemurs & Fruit-eating Bats Brit. Mus., 130-131, 1870. 
Species: Mico sericeus Gray, and Hapale chrysoleucos Wagner, from Brazil. 
Micoella: Dim. of Mico. 
Micoureus Lesson, 1842. Marsupialia, Didelphyide. 
Nouv. Tableau Regne Anim., Mamm., 186, 1842; THowas, Cat. Marsup. 
Monotrem. Brit. Mus., 540, 1888 (type fixed). 
Species, 8: Micoureus cinereus (= Didelphys cinerea Temminck, type), from Brazil; 
M. dorsigera (Linneeus), from Dutch Guiana; M. murina (Linneeus), from 
Guiana; M. tricolor (Geoffroy), from Guiana and Brazil; M. lanigera (Desmar- 
est) from Paraguay; M. elegans (Waterhouse), from Chile; M. californicus 
(Bennett) and M. breviceps (Bennett), from ‘ California’ (Mexico). 
Micoureus: Micouré, name of an opossum, used by the Gaurani Indians of Paraguay. 
Microbiotherium AMEGHINO, 1887. Marsupialia, Microbiotheriide. 
Enum. Sist. Especies Mamif. Fós. Patagonia Austral, 6-7, Dec., 1887. 
Species: Microbiotheriwm patagonicum Ameghino, and M. tehuelchum Ameghino, 
from the Lower Tertiary of the Rio Santa Cruz, Patagonia. 
Extinct. 
Microbiotherium: uiepófhios, short-lived; 670íov, wild beast. 
Microcavia H. Gervais & AMEGHINO, 1880. Glires, Caviidee. 
Mamm. Foss. Amérique du Sud, 50-55, 1880. 
Species, 4: Microcavia typus Gervais & Ameghino, M. robusta Gervais & Ameghino, 
M. intermedia Gervais & Ameghino, and M. dubia ( — Cardiodus dubius? Bra- 
vard), all from the pampas of the province of Buenos Aires, Argentina. 
Extinct. 
Microcavia: ui«pós, small*; + Caria. 
Microcebus Grorrroy, 1834. Primates, Lemuridee. 
Cours Hist. Nat. Mamm., 11* Lecon for June 6, 1828, 24-26, 1834; Martin, Proc. 
Zool. Soc. London, 1835, 125-127; FonsvrH Masor, Novit. Zool., I, 6-17, 1894. 
Type: ee ee Geoffroy, from Madagascar 

*The Dee TNR small, usually requires no further explanation than that it 
indicates relative size. 
