136 



which curves downwards and backwards on the lip for a short distance, 

 and then taking an upward curvature, passes in front of the eye, and 

 is lost in the fur of the forehead. 



All the membranes, both above and below, have those parts con- 

 tiguous to the body, hairy, especially the interfemoral, on which it 

 extends more markedly than elsewhere. The part of the latter mem- 

 brane which is destitute of hair, is smooth, and has about ten trans- 

 verse strongly dotted lines. 



Over the whole of the body the fur is very thick, soft, and rather 

 long. On the top of the head it is long enough to obscure the basal 

 half of the ears, and thus give the appearance of an elevated crown. 



Everywhere the hair is unicoloured, and of a black-brown colour 

 on the head and back, passing into chestnut-brown on the rump. 

 Beneath it is similar in colour, but more strongly tinged with brown, 

 especially towards the pubal region, where it is reddish-brown. 



On examining the cranium, I find that its chief peculiarity consists 

 in its extreme shortness in relation to its other dimensions. In this 

 respect it more nearly resembles the cranium of Lasiurus novebora- 

 censis than that of any other species of bat I have yet seen, but it is 

 even shorter than in that species. In its general conformation it 

 bears considerable resemblance to that of the common Pipistrelle of 

 Europe, especially in the degree of elevation of the cerebral region ; 

 but the arrangement of the dental series is more like that of the 

 Noctule Bat than that of the Pipistrelle, but bears a still greater 

 resemblance to that of the Scotophilus Gouldii of Australia. Thus, 

 on examining the teeth of the upper jaw, they are seen to be arranged 

 in two straight lines which are nearly parallel, the incisors only de- 

 viating from these lines, being placed across the front of the space 

 enclosed by them. This enclosed space — constituting the anterior 

 part of the palate — is nearly a parallelogram, being but slightly nar- 

 rower in front than posteriorly. Its length to its breadth is as one 

 and a quarter to one. 



The range of the teeth in the lower jaw must, of course, bear exact 

 relation to that of the upper *, varying only in the number of the 

 teeth and their individual form. 



* It will not be out of place here to remark, that this expression applies ex- 

 clusively to the normal state of dentition of animals in a state of nature. The 

 reverse of this may occasionally be seen in accidental varieties or malformations, 

 and frequently in domesticated animals, where a great change in the form of the 

 jaws and teeth has often resulted from long-continued selection of individuals 

 from which to produce a breed for some special purpose, which selection may 

 have been further assisted by a constant training to the purpose for which the 

 breed was designed. This must certainly be the case with some of the varieties 

 of dogs. In the bull-dog, for instance, we find a most remarkable development 

 of lower jaw, attended with an equally distorted arrangement of the teeth. It 

 is scarcely necessary to allude to the singular appearance often observable in the 

 front teeth of the human species, under- or over-lapping each other, as the case 

 may be, and displaying every degree of intermediate arrangement. But these 

 deviations from the normal state of dentition in no way affect the statement above 

 made respecting the relation of the inferior to the superior maxilla, and their im- 

 planted teeth. 



