y6 NEW YORK STATE MUSEUM 



104 Pipistrellus subflavus (F. Cuvier): American pipistrelle, p. 150 



Represented by: 



Pipistrellus subflavus subflavus (F. Cuvier): south- 

 eastern pipistrelle, p. 150 



Pipistrellus subflavus obscurus Miller: northeast- 

 ern pipistrelle, p. 150 



Genus Vespertilio Linnaeus: p. 151 



105 Vespertilio fuscus Beauvois: big brown bat, p. 151 



Represented by : 

 Vespertilio fuscus fuscus Beauvois : eastern big brown 

 bat, p. 151 



KEY 



Class Mammalia Mammals 



Vertebrate (backboned) animals with four chambered heart, complete double 

 circulation, body partly or wholly covered with hair (rarely almost naked) ; 

 young nourished for a period afterbirth by milk; breathing accomplished by 

 means of luugs (Mammalia; Lat., a nipple). 



The Mammalia are distributed over practically the whole surface of 

 the earth and throughout the oceans. They are absent however from 

 the most extreme arctic and antarctic regions. The class is divided into 

 three subclasses: i) the Prototheria, in which the young are 

 hatched from eggs as in birds, confined to New Guinea, Australia, and 

 Tasmania; 2) the Metatheria, in which the young are born in a 

 very rudimentary condition and after birth carried for some time at- 

 tached to the nipples of the parent (usually in a special pouch of skin) ; 

 and 3) the Eutheria, in which the young are born perfectly formed. 

 While the Metatheria comprise the one order Marsupialia, a 

 single representative of which occurs within our limits, the Eutheria 

 are divided by Flower and Lydekker^ into 9 orders. Of these 7 are ter- 

 restrial, and members of each are found in North America. Six come 

 within the scope of the present paper. 



ORDERS 



Female generally (always in North American species) 

 provided with an external ponch iu which the young 

 are carried for sometime after birth, Metatheria 

 (in species found within our limits, tail prehensile, 

 teeth 50, hind foot with 5 toes, the innermost of 

 which is thumb-like and clawless) (opossums) Marsupialia, p. 77 



1 An introduction to the study of mammals living and extinct. 1891. 



