MAAIMALIA.— DENTITION OF MAMMALS. 139 



The Lemttria are mostly distinguished by a vulpine muzzle, with separated incisors in the upper jaw, those of 

 the lower directed horizontally forward, as are also the inferior canines, which the author reckoned as a third pair 

 of incisors. Their cheek-teeth are often sharply tuberculated ; and the doubling- down of the ears in some, the 

 character of the fur, the particular structure of the female reproductive organs, nocturnal habits, and a variety of 

 other characters, forcibly recall to mind the insectivorous Bats. Among^ them, the genus Cheirogaleus is remark- 

 able for the total absence of superior canines; and that of C^Wro;nj/« for having rodent canines, which pass 

 through the intermaxillary bones, and supply the place of incisors, which are altogether wanting. 



The Cheiroptera have never more than four incisors to the upper jaw, but commonly six below, which is the 

 normal complement. Amongst their less obvious distinctive characters from the other Primates, may be mentioned 

 the constant absence of any coecum, and the presence of a small os penis within the glans, but different from that 

 of ordinarj' occurrence among the Secundates, They are born with their eyes closed. Following the fancy of 

 Linnaus in applying the name Lemur to the preceding group, we propose to designate the two principal divisions 

 of Cheiroptera, — Harpydia and Spectra, which, in various respects, are analogous to the Anthropida and Lemima. 



The Harpydia have blunt molars, an extremely elongated stomach, and long intestines ; also a sonorous voice, 

 and most usually a claw to the fore-finger. Though stated to feed, in some instances, partly on insects, we have 

 reason to believe (from recent observation of a living animal, which invariably rejects all insect-food that is offered 

 to it,) that they are exclusively frugivorous. All are peculiar to the eastern hemisphere. 



The Spectra have a globular stomach, short intestines, and sharp tubercles to the molars, except in the very 

 extraordinary' genus Desmodus, which, for reasons connected with its habits, has no true molars whatever. They 

 have a clicking voice, and no claw to the fore-finger, &c. 



The second sub-order of Typodontia, or the Feris, or Sec>indatei>, subdivides into the obvious groups Carnivora 

 and Insectivora of Cuvier; but as these names are equally applicable to Marsupial genera, and therefore particu- 

 larly liable to mislead, by inducing the erroneous supposition that they apply to all carnivorous and insecti- 

 vorous Mammalia respectively, in which significant general sense they might still he employed with con- 

 venience, just as the analogous terms Herbivora and Frugivora are at present, we believe that they might 

 advantageously be disused in their restricted and forced meaning, to be superseded by names of more special 

 application. "We therefore venture to designate them Cynodia and Ecanina. It is in this division that the four 

 different sorts of teeth assume their most distinctive characters, as it is unnecessary to dwell upon. The incisors 

 are rarely less than six in number, in either jaw. 



In the Cynodia, the canines are always present, both above and below, and are invariably strongly characterized 

 as such ; and the incisors form a transverse range, the outer pair, more particularly those above, being always 

 largest, and the medial smallest. They fall into four subtribes, viz., Digitigrada, Subplantigrada, Plantigrada, and 

 Pinnigrada ; the first and last of which are constantly furnished with a coecum, which does not occur in the others. 



Tlie Digitigrada are not always digitigrade, but the term need not on this account be altered. We adopt the 

 group as instituted by Cuvier, detaching only the first leading subdivision, or that of the Weasels and allied genera. 



The Subplantigrada have never more than one true molar above, and another below, which vary exceedingly in 

 developement, in an inverse ratio to the carnassier, or scissor-tuoth, — the Weasels and Badgers exhibiting the 

 extremes. The great and small intestines scarcely differ in calibre; and all, unless the Otters constitute an excep- 

 tion, can diffuse at will a disgusting stench. None of them fall into a torpid state during the winter, like the northern 

 Plantigrada. Their hind feet are always semi-plantigrade, but none of them bring the heel quite to the ground. 



The Plantigrada have constantly two pairs of true molars in each jaw, which likewise vary exceedingly in de- 

 velopement, and in an inverse ratio to the scissor-teeth, which in the Bears are reduced to their minimum 

 throughout the Cynodia. In their plantigrade gait, and generally naked sole (not naked by friction merely, as in 

 the Badgers), their tendency to torpor during severe weather, and a variety of other particulars, a direct affi- 

 nity to the i/iAfc^/fo/a, Cuv., is very apparent ; and the Raccoons among them are further remarkable for the 

 entire separation, and a certain amount of prehensibility of the toes, which last enables them to clasp small objects 

 in a manner observed in no other Secundates, — the rest of the Cynodia having a membrane more or less developed 

 between the toes. The skull of the Bears exhibits various tokens of affinity with the next group. 



The Pinnigrada, or 5-eals, cnrrespond to the Amphibia of Cuvier, and are remarkable for the similarity of their 

 true and false molars ; the former of which, however, in no instance, exceed the typical number. 



The Ecanina, or second and abnormal subtribe of Secundates (being the Insectivora, Cuv.), have an attenuated 

 muzzle, and mostly separated incisors that face laterally, the medial or foremost being always largest, as in the Pri- 

 mates; no true upper canines, but very commonly an eiilaiged false molar with two fangs, that presents the appear- 

 ance and performs the office of a canine, the lower canines being always present (unless in the Shrews), but commonly 

 very small, and hence ranked as a fourth pair of incisors. They have generally three true molars, both above and be- 

 low, and always perfect clavicles, which is the case in no species of Cynodia. The genera Macroschelides and Tiipaia 

 alone possess a coecum ; and the Shrews.which have no incisors, nor even intermaxillary bones that should contain the 

 upper ones, are remarkable for possessing two very curious front teeth, which we suspect are modified false molars. 



We shall offer no further remarks on the Isodontia, or Cetacea ordinaria of Cuvier, than to observe, that 

 the Narwhal alone among them possesses other than false molars. 



The DiPLODONTiA, or normal order of the great phytophagous type, divides first into hrochata and Ungulata, 

 the njimes of which require to be admitted with some reservation, though certainly not with more than — nor indeed 

 so much as — i\vQ Edentata of Cuvier. They have always a voluminous coecum, with the single, and consequently 

 very remarkable, exception of the small Dormouse group. 



The Brochata have ordinarily (at least the three first principal divisions of them) permanently growing canines, 

 which either pass through the intermaxillaries, as in the Elephants and 'Kodenti— deriving their nutriment, how 



