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Show 284 MR. ST. GEORGE MIVART ON ANUROUS BATRACHIANS. [May 13, tongue and digital disks-which latter I decline to select. This character is the presence of maxillary teeth. O n this subject Dr. Giinther observes*, " W h e n we consider that the lower jaw of the tailed Batrachians is provided with a series of teeth, and that these are wanting in all the tailless Batrachians, we are obliged to acknowledge the importance of this character." Since this was written, however, two forms have been discovered which arc provided with mandibular teeth f; and this m ay perhaps be considered to strengthen Dr. Giinther's refusal to consider the possession of teeth a primary character-a refusal he fortifies by reference to the Edentata and Salmonidae. But the learned Doctor's refusal was mainly grounded on his **' not being able to consider the character of the dentition among the tailless Batrachians as one intimately connected with their mode of life"*}:, an objection the force of which I a m so far from being disposed to admit that I would select for classificatory purposes the least adaptive characters I could find, provided they were constant and easilv to be ascertained. It is true that in the Edentata we have edentulous and many toothed forms, but then these forms are very distinct; we have no edentulous Armadillos and no toothed Ant-eaters, and indeed the order may well be primarily divided according to the dentition; so that I think that, on the whole, the Edentata favour m y view. Characters as to dentition serve also to define the primary divisions of the orders Primates, Chiroptera, Insectivora, Cetacea, and Marsupialia, at the least, if not others also ; and the edentulous Chelonia form the most natural and well-defined primary groups of existing Reptiles. Mr. Cope opposes the adoption of dental characters for important divisions as follows:-"The increase of knowledge furnishes us with cases of rudimental dentition, indicating a less significance for the character which has been supposed to characterize the Bufoniformia. Such occurs in the genus Cotostethus, Cope, which seems to be quite identical with Dendrobates, except in the possession of teeth. Micro-hyla, a true Engystomatid, is said by Dr. Gunther to possess teeth ; and minute rugosities on the maxillae of Callula natatrix deceived m e into the belief at one time that teeth actually existed. Among arciferous genera Eupemphix (Steindachner) is said by him to possess very minute teeth, which in some adults are entirely wanting " § . To this it m a y be replied that the loss of teeth in certain individuals, perhaps aged, can hardly be a valid reason to reject this character as one of weight. Secondly, Microhyla does not possess teeth ; the possession of teeth was attributed to it by Dr. Giinther on the * Proc. Zool. Soc. 1858, p. 340. t These are:-Hemiphractus scutatus, described by Peters, in ' Berlin Monats.' 1863, p. 144; and Grypiscus, described by Cope in 'Journal of Acad. Philadelphia,' 1867, vol. vi. part 2, p. 205. \ Proc. Zool. Soc. 1858, p. 340. § Journal of the Acad, of Nat. Sc. of Philadelphia, new series, vol. vi. part 2, p. 189. |