Gidley, James Williams, 1866-1931.2005-10-062005-10-061904http://hdl.handle.net/2246/1517p. 191-194 ; 24 cm.Includes bibliographical references."The chief distinguishing characters of the American Miocene genera as now understood may be given briefly as follows: Hypohippus: Both deciduous and permanent series of teeth brachyodont, no cement; both upper series without external ribs on paracone and metacone; metaloph simple and undivided, but strongly united with the ectoloph; no crochet; metaconid and metastylid of lower teeth undivided or slightly divided by a shallow notch at the summit of an unworn tooth. Parahippus: Both deciduous and permanent series of teeth brachyodont, deciduous series without cement, permanent series sometimes lightly cemented; deciduous upper molars with prominent external ribs on paracone and metacone; metaloph strongly united with ectoloph; crochet well developed, uniting more or less strongly with the protoconule; metastylid strongly developed, with well-marked groove separating it from the metaconid. Merychippus: Deciduous molars brachyodont with little or no cement; permanent series short hypsodont, fully cemented. Protohippus: Both deciduous and permanent series of teeth hypsodont and strongly cemented; permanent series moderately long-crowned; crowns much curved; protocone and protoconule strongly united; fossettes or cement lakes wide transversely with open loops, and usually with comparatively simple enamel borders. Neohipparion: Both deciduous and permanent series of teeth hypsodont and strongly cemented; teeth of permanent series usually longer crowned and upper teeth less curved than in Protohippus; protocone free to near its base as in Hipparion"--P. 194.1334308 bytesapplication/pdfen-USQH1 .A4 vol.20, art.15, 1904Horses, Fossil -- America.Horses, Fossil -- Nomenclature.Mammals, Fossil -- America.Paleontology -- Miocene -- America.Paleontology -- America.text