414 INDEX GENERUM MAMMALIUM. 
Mesocricetus—Continued. 
Mesocricetus: jeé6os, middle; --Cricetus—indicating its intermediate position 
between Cricetus and Cricetulus. 
Mesocyon Scort, 1890. Ferze, Canidee. 
Princeton College Bull., II, No. 2, p. 38, Apr., 1890; Hay, Science, new ser., X, 
254, Aug. 25, 1899; Cat. Foss. Vert. N. Am., Bull. 179, U. S. Geol. Surv., 773, 
1902. . 
Type: Temnocyon corypheus Corr, from the Miocene of John Day River, Oregon. 
Extinct. Based on a left ramus. 
Mesocyon: 1L éG Oc, middle; «vcv, dog. 
Mesodectes Corr, 1875. Insectivora, Leptictidee. 
Syst. Cat. Vert. Eocene New Mexico, 30 footnote, Apr. 17, 1875; Rept. U. 8. 
Geol. & Geog. Surv. Terr., III, 801, 1884. 
New name for Jsacus Cope, 1873, which is preoccupied by Jsaca Walker, 1857, a 
genus of Hemiptera. 
Mesodectes: €605, middle; 6”7Kr7s, biter. 
Mesodiodon Duvernoy, 1851. Cete, Physeteridze. 
Ann. Sci. Nat., Paris, 3° sér., XV, Zool., 41, 55-56, 68-69, pl. 2 figs. 2, 2’, 1851. 
Mesiodon Gray, Cat. Seals & Whales Brit. Mus., 349, 1866 (synonym of Ziphius); 
ManscHuanLL, Nomenclator Zool., 8, 1873 (misprint). 
Type: Dioplodon sowerbyi Gervais ( — Delphinus sowerbyi Desmarest), from Brodie, 
Elginshire, Scotland. 
Mesodiodon: uéGoc, middle; 67- two; 65@v=6do0vs, tooth—in allusion to the two 
prominent teeth in the lower jaw (one on each side), usually some distance 
behind the apex of the ramus. 
Mesodon AMEGHINO, 1882. . Edentata, Megatheriide. 
'* Cat. de la Sec. de la prov. de Buenos Aires, Exp. Cont. Sud-Am., 41, 1882" 
(fide AwEGHINO, Act. Acad. Nac. Cien. Córdoba, VI, 738, 1889, under Glosso- 
therium zeballosi). 
Type: Mesodon zeballosi Ameghino, from the Pampean formation of the Province 
of Buenos Aires, Argentina. 
Name preoccupied by Mesodon Rafinesque, 1819, a genus of Mollusca; and by 
Mesodon Wagner, 1851, a genus of Pisces. 
Extinct. 
Mesodon: uéGoc, middle; 66@v=d6o0vs, tooth. 
Mesodon (see Mesoodon). Cete, Physeteridee. 
Mesogaulus Riaas, 1899. Glires, Castorid:e (Mylagaulidz). 
Field Columbian Mus., Pub. 34, Geol. ser., I, No. 4, pp. 181-183, 3 figs., Mar., 1899. 
Type: Mesogaulus ballensis Riggs, from the Deep River escarpments ( Miocene), near 
White Sulphur Springs, Montana. 
Extinct. Based on a mandible. 
Mesogaulus: sé6os, middle; +-(Myla-) gaulus—i. e. a Miocene Mylagaulus. 
Mesohippus Mansu, 1875. Ungulata, Perissodactyla, Equidee. 
Am. Journ. Sci. & Arts, 3d ser., IX, 248, Mar., 1875. 
Type: Anchitherium bairdi Leidy, from the Oligocene (White River) of South 
Dakota. 
Extinct. 
Mesohippus: u£Gos, middle, intermediate; zazos, horse—i. e., intermediate be- 
tween Orohippus and Miohippus. 
Mesolama AmeEGHINo, 1884. Ungulata, Artiodactyla, Camelidee. 
Bol. Acad. Nac. Cien. Córdoba, VI, entr. 2-3, p. 199, 1884; Cont. Conocimiento 
Mamíf. Fósil. Repüb. Argentina, in Act. Acad. Nac. Cien., Córdoba, VI, 
589-590, pl. xxxv, fig. 3, 1889. 
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