1855.] 431 



says he found it in South Carolina, but brought none thence to France, as the skin 

 was so thin and tender, that he was unable to preserve or even describe it : to 

 me the skin appears as strong as that of any other species of Ranina of the same 

 size. 



These are all the species of this family of reptiles which I have been able to 

 see in a living state. I hold it to be impossible for any one to make a correct 

 description of an animal which has the power of changing its color at will, un- 

 less he has it alive ; and this power they all possess in a greater or less degree ; 

 when preserved in alcohol they always fade. The difficulty of procuring de- 

 scriptions made on the spot where the objects are found, has rendered this part 

 of natural history as confused and unsatisfactory, as the researches of bota- 

 nists who draw up their accounts of plants from dried specimens. 



There are a few species with which I was formerly acquainted but which I 

 have not met with or been able to obtain. Among these are a frog which seemed 

 intermediate between R. pipiens and R. palustiis, two Hylae inhabiting Georgia, 

 and another probably an Acris which I formerly described in the Annals of the 

 Lyceum of New York under the name R. pumila. Mr. Baird describes some 

 in the Proceedings of our Society, which have been sent to him from Texas, 

 Mexico, and other remote parts of our country. These I do not here treat of, 

 being certain that I shall never see them in a living state. There is in the 

 waters of ponds and ditches a small frog whose note exactly resembles the bleat- 

 ing of a lamb, so truly as to deceive any one. This animal I have seen, but 

 never succeeded in catching it. It is very common in Georgia and I have 

 heard it as far north as Norfolk in Virginia. It is left to the inhabitants of those 

 parts of our country to determine what it is. 



Observations on the North American species of Bats. 



By John Le Conte. 



Notwithstanding all that has been written by Rafinesque, F. Cuvier and Dr. 

 Bachman on the bats of North America, a diligent study has shown me consid- 

 erable errors in the accounts of all. Before proceeding to a description of these 

 animals, it is necessary to remark, that every bat which I have seen, has an uncer- 

 tain numberof transverse wrinkles or plaits on the outer portion of the ear, and has 

 the toes furnished with rather long and fine hairs, as it were fimbriated, wherefore 

 these two marks are omitted as furnishing no good specific characters. All our bats 

 except the Molossus belong to the same genus ; the trifling difference in the 

 number of the teeth does not afford a sufficient reason for considering them as 

 different. M. F. Cuvier in the first volume of the Nouv. Annales du Museum, 

 divides the genus into three sections, the Serotinoids, the Noctuloids and the 

 Murinoid?. The form of the cranium seems to be the chief mark in distin- 

 guishing them from each other. The Serotinoids may be described as having 

 the cranium somewhat inflated and rounded, the jaws short, widened and ele- 

 vated at the extremity, the facial angle 43. The European species as far as I 

 can collect, have four upper incisors. In this country we have but two belong- 

 ing to this section, the Noveboracensis and the cinereus, both of which have but 

 two upper fore teeth. The Noctuloids have the skull rather straight and flat on 

 the top, and the jaws more extended, the facial angle is 30. They all have 

 four upper incisors except the crepuscularis which has like those of the first di- 

 vision but two. The Murinoids are known by having the cranium inflated and 

 rounded, the jaw3 elongated a little raised in front with a considerable depres- 

 sion separating them from the cranium, the facial angle is 22. The V. pallidus 

 which has buc two upper fore teeth appears to me to be a Murinoid ; all the 

 rest have four upper fore teeth. As for what has been called a Plecotus (even 

 by myself) it certainly belongs to this division : it differs considerably from 

 the Plecotus auritus of Europe, in the form and position of the ears. I am not 

 writing about the animals of a foreign country, and therefore I say no more on 



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