37 



near to the sides of the body, exhibit a singularly spotted appear- 

 ance, occasioned by the network of veins being paler in colour than 

 the portions enclosed by them. It was probably to one of these 

 that Raffinesqne applied the appropriate epithet "■ tessellatus." The 

 example in which I have seen this peculiarity most conspicuous, was 

 obtained in the Island of Mackinac, between Lakes Huron and Mi- 

 chigan, by my friend Mr. P. L. Sclater, who, knowing how much I 

 am interested in this order of Mammals, kindly presented it to me, 

 with other North American Bats collected by him in the autumn of 

 1856. 



Dentition. — In. 



C^! PM — M — — - 

 \j. Vl , x.iu. 2 . 2 , 1U. 3.3— 18 . 



The first pre-molar on each side in the upper jaw is small and 

 rudimentary, and perhaps is sometimes wanting. It is placed in the 

 angle between the canine and the contiguous pre-molar, in such a 

 manner as not to be visible from the outside. 



Length of the head and body. 



of the tail 



of the head 



- of the ear 



of the tragus 



■ of the fore arm 



of the longest finger . 



1. 





2. 





3. 



4. 



In. Lines. 



In. 



Lines. 



In. 



Lines. 



In. Lines. 



2 1 



2 



1 



2 



2 



1 11 



1 11 



2 







2 







1 10 



8^ 







8 







8 



74 



3 







3 







3 



3 



2 







2 







2* 



2 



1 7 



1 



6* 



1 



7* 



1 H 



3 3 



3 



2 



3 



5 



3 2 



In. 



Lines. 



2 



7 







'"n 







3* 







2* 



1 



5i 



2 



11 



2. Lasitjrus pruinostjs, Say. 



Vespertilio pruinosus, Say, Long's Exped. Rock. Mount, i. p. 168, 

 1825 (?) ; De Kay, Nat. Hist. New York, i. ; Fisch. Synop. Mam. 

 p. 1 13 ; Godm. Amer. Nat. Hist. i. p. 68 ; Harl. Faun. Amer. p. 21 ; 

 Coop. Ann. Lye. N. H. New York, iv. p. 54. 



Scotophilus pruinosus, Gray, Mag. Zoo\. Bot. ii. p. 498, 1838. 



Nycticejus pruinosus, Temm. Mon. ii. p. 154, 1835-41 ; Wagn. 

 Snpp. Schreib. i. p. 544 ; Schinz. Synop. Mam. i. 197. 



Lasiurus pruinosus, Gray, Cat. Mam. Brit. Mus. p. 32, 1843. 



Vespertilio cinereus, Palisot de Beauvois, Cat. Peale's Museum, 

 1796. 



It is not unusual to see the name of this species attached to spe- 

 mens of the former, an error not easy to commit, if actual comparison 

 of the two were made. The present one is greatly superior in size 

 to the last, and besides this, presents some other very distinctive 

 characters* 



The head is broad, and the forehead flat ; the muzzle is obtuse ; 

 the nostrils are surrounded by a well-defined rim, are directed sub- 

 laterally, and separated by a considerable interval, which is emar- 

 ginate. The ears are irregularly round, their front margins project- 

 ing considerably over the forehead. Their outer or hinder margins 

 are brought forward along the sides of the face in the shape of nar- 

 row prolongations, and terminate in two slightly projecting lobes 

 behind the corners of the mouth. The tragus appears to offer some 

 slight variations of form in different individuals, and even in the 



