Geological magazine . pe; the results of thisinvestigation being published in a memoir issued under the auspicesof the Museum of Harvard College.^ Since these results are of con-siderable morphological importance, and are especially interestingto palaeontologists, a short resume of them may be acceptable to our1 Bull. Mus. Comp. Zool. Harvard Coll. vol. zx. pp. 87, e6 seq. (1890). 318 Reviews—Prof. H. F. Osborn—Molars of Perissodactyla. readers. For this piirpose Prof. Osborn has been good enough toplace at our disposal cliches of some of the figures illustrating hismemoir; which figures, with
Geological magazine . pe; the results of thisinvestigation being published in a memoir issued under the auspicesof the Museum of Harvard College.^ Since these results are of con-siderable morphological importance, and are especially interestingto palaeontologists, a short resume of them may be acceptable to our1 Bull. Mus. Comp. Zool. Harvard Coll. vol. zx. pp. 87, e6 seq. (1890). 318 Reviews—Prof. H. F. Osborn—Molars of Perissodactyla. readers. For this piirpose Prof. Osborn has been good enough toplace at our disposal cliches of some of the figures illustrating hismemoir; which figures, with some of our own, we reproduce. It may be well to premise our observations by stating that theupper molars of the Perissodactyles are constructed on what isknown as the lophodont type; this modification consisting of anouter wall, connected with two more or less nearly complete trans-verse crests inclining backwards. The simplest modification of thistype of molar is to be found in the little HyracotJieriiim of the. n^^tn.^nvef Fig. 1.—Left upper premolar and molar teeth of Anchifheriiim [Mesohippus) protocone; pp. posterior prominence. London Clay ; but those of the generalized Horse-like animal knownas Anchitherium (including Mesohippus) are but little more this genus we reproduce two of Prof. Osborns figures; one(Fig. 1) showing the whole series of cheek-teeth, and the other(Fig. 2) a single molar. One species (Fig. 1) is a smaller and simplerform, in which the tubercle marked pp is less developed than inthe larger species (Fig. 2). In these teeth there is no difficulty inrecognizing the six elements of the sex-tubercular tooth, all of which are indicatedby letters in Fig. 2, with the exception ofthe metaconule, which is the unletteredridge occupying the middle of the tooth,immediately below the m. The fourremaining elements, lettered a. m. p. andpp., have been developed from the basalcingulum surrounding the molar of JSyra-cotherium; and, accordi
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Keywords: ., bookcentury1800, bookdecade1860, booksubjectgeology, bookyear1864
