432 [December, 



this head, than that the P. aurilu3 as far as regards the skull appears to be a Seroti- 

 noid. My remarks on the Molossus will appear when I come to describe that 

 species. 



Vespertilio noveboracensis Linn. New York bat, Pennant Arctic Zool. 

 vol. i. p. 184. V. rubellus Palisot de Beauvois, Catalogue of Peale's Museum. 

 V. monachus and tessellatus Rafinesque. Nycticeius Atalapha and Atalapha 

 americana ejusd. Taphyzous rufus Lesson. It likewise belongs according to 

 Leach to his genus Scotophilus, Taphizous rufus. Harlan's description is made 

 from an infamous figure in Wilson's Ornithology. 



Dentition. Upper Jaw, incisors l-l simple, distant. Canines 1-1, hollowed 

 out behind with a perpendicular septum dividing the concavity for its whole 

 length False molars 1-1, concave on the outer and inner surfaces, the calca- 

 neum produced behind into a lobe. Molars 3-3, the first and second with six 

 cusps, three exterior, small apparently formed from the basal ridge which sur- 

 rounds the teeth ; two intermediate and one exterior ; the third with three cusps 

 ranged transversely and one posterior. 



Lower Jaw. Incisors six, biemarginate. Canines 1-1. False molars 2-2, the 

 anterior one very small. Molars 3-3, with five cusps, two exterior and three 

 interior, the basal ridge wanting interiorly. 



A young one taken from the mother's breast, had in the upper jaw, the inci- 

 sors, the canines, and the false molars; in the lower jaw, the canines and 

 one false molar on each side, all of them hooked like the claws of the toes. 



Face black, hairy ; nose blunt, emarginate. Ears brown, short, round, almost 

 concealed in the fur, a little hairy, orillon cultriform, blunt, one half the length of 

 the ear, and sparely hairy. Membrane dusky, generally reddish brown along 

 the antibrachium, and more or less so along the great part of the length 

 of the fingers ; a portion of the base on each side is hairy, so as to form a straight 

 line from the shoulder to the foot ; spot at the base of the thumb white, a few 

 hairs of the same color or of rufous extend down the fourth finger: beneath 

 from the body to the end of the os humeri it is thickly covered with rather long 

 hair, along the fore arm more sparsely so, for nearly one half the w r idth 

 of ihe wing. The interfemoral membrane includes the whole of the tail, 

 on the upper surface it is densely hairy, the hair being of the general color 

 of the body, sometimes tipped with white, never cinereous at the base ; on the 

 under surface it is naked except at the base, where there is an oblong patch of 

 hair extending along the tail, for one third of its length. Feet black, thickly 

 covered with hair. 



Color extremely various, scarcely any two being found exactly alike. A very 

 common variety has the hair above four-colored, that is to say, black or dark 

 cinereous at the base, then yellowish brown or fawn-colored, afterwards dark ru- 

 fous or reddish brown, or orange-tawny or purplish brown, finally very slightly 

 tipped with white, very often with a distinct ring of a darker shade around the 

 neck. Beneath, the hair is three colored, the base dark or light cinereous, then 

 one of the other colors, and tipped with white, so that the pelage is varied 

 with cinereous and the other colors, and powdered over with white : this last 

 color forms a conspicuous spot at the axilla. The pelage is however above 

 sometimes only three-colored, being as before dark cinereous at the base, then 

 pale yellowish, and afterwards bright light rufous or orange without any white 

 tips or very few of them, so as to appear uniformly rufous or orange, be- 

 neath rather paler. The lighter the color above, the more does the membrane 

 incline to reddish brown. They have been found of a uniform cream color, and 

 even white, the base of the hair being always cinereous, but are most com- 

 monly of different shades of rufous or tawny. The darker the ground the 

 more apt are the hairs to have white tips, although some of dark shades have 

 been found without any of these. 



Length 2 in. Tail 1.6. Extent 11.3. Head -7. Ears -25. Orillon -1. 



This, the commonest species in the United States, is found everywhere from 

 Canada to Florida, from one end of the country to the other equally numerous. 

 It may even extend into South America, as the description by Lesson of the V. bo- 



