MESOTHERIUM—METAEPANORTHUS. 41^ 
Mesotherium-— Continued. 
Type: Mesotherium cristatum Serres (1867), collected by M. Séguin in Argentina. 
“Un genre nouveau, que nous proposons de nommer Mésothérium (désigné 
provisoirement par M. Bravard sous le nom de Typothérium )." 
Extinct. 
Mesotherium: é60s, middle; 6yetov, wild beast—in allusion to its supposed re- 
lationships with the Edentates, Rodents, and Pachyderms. 
Mesotherium FrirLnor, 1880. Ungulata, Artiodactyla, Anoplotheriide. 
Comptes Rendus, Paris, XC, No. 26, pp. 1579-1580, Jan.-June, 1880. 
Type: Mesotherium mirabile Filhol, from the Phosphorites of Quercy (Upper 
Eocene), near Caylux, France. 
Name preoccupied by Mesotheriuin Serres, 1857, a genusof Typotheriidz. Replaced 
by Metriotherium Filhol, 1882. 
-Extinct. Based on ‘‘un maxillaire inférieur de Pachyderme à dents en série 
continue." 
Mesotherium: 4 éGos, middle; 67píov, wild beast—in allusion to its molars, which 
are intermediate in character between those of Anoplotherium and Pachynolophus. 
Mesotherium Moreno, 1882. Marsupialia, ? 
** Patagonia, Resto de un Contiente hoy sumergido, 25, 1882"' (fide AMEGHINO), 
AMEGHINO, Act. Acad. Nac. Cien., Córdoba, VI, 267-268, 1889. 
Type: Mesotherium marshii Moreno (nomen nudum), from the Rio Negro, near the 
confluence of the Limay and Neuquen, northern Patagonia. 
Name preoccupied by Mesotherium Serres, 1857, a genus of Typotheria; and by 
Mesotherium Filhol, 1880, a genus of Artiodactyla. Replaced by Mesitotheriwm 
Trouessart, 1883; and by Macropristis Ameghino, 1889. 
Extinct. Based on part of skull. 
Metacheiromys Wortman, 1903. Primates ( Metacheiromyidz). 
Am. Journ. Sci., 4th ser. [XV, 176, 401, 1903, nomen nudum;] XVI, 347-352, 
figs. 105-109, Nov. 1903. 
Type: Metacheiromys marshi Wortman, from the Bridger Eocene of Wyoming. 
Extinct. Based on a fragmentary skeleton, including two upper incisors, a 
mandibular ramus, and a number of fragments of bones. 
Metacheiromys: meta, next to*; + Cheiromys. 
Metachirus (subg. of Didelphis), BurMetsTER, 1854. Marsupialia, Didelphyide. 
Syst. Uebers. Thiere Brasiliens, I, Sáugeth , 135-137, 1854; THomas, Cat. Marsup. 
& Monotrem. Brit. Mus., 329, 1888 (type fixed). 
Species, 4: Didelphys myosurus Temminck (=D. nudicaudata Geoffroy, type, from 
Cayenne), D. quica Natterer, D. cinerea Maximilian, and D. incana Lund, from 
Brazil. 
Metachirus: uer«&, behind; yeip, hand—in allusion to the absence of webs 
between the toes of the hind foot, in contrast with Chironectes, in which the 
hind toes are webbed. 
Metadichobune Firuor, 1877. Ungulata, Artiodactyla, Anoplotheriide. 
Bull. Soc. Philomathique, Paris, 7° sér., I, 53, 1877; Ausron, Zool. Record for 
1878, XV, Mamm., 17, 1880. 
Type: Dichobune campichei Pictet, from the Eocene of Europe. 
Extinct. 
Metadichobune: joerc, next to, next after; -- Dichobune. 
Metaepanorthus Amecuino, 1894. Marsupialia, Epanorthide. 
Enum. Syn. Mamm. Foss. Form. Eocénes de Patagonie, 92-93, fig. 39, Feb., 1894. 
*'The prefix Meta- is generally used to indicate the relative systematic position of 
the genus, or, in the case of extinct forms, the relative time of occurrence. Its use 
in Metachirus is exceptional. 
T591— No. 23—03 

bo 
-l 
