NORTH AMERICA AND THE WEST INDIES 15 



olive-buff (Jackson); tail buffy brown to tawny olive above, 

 below nearly "tilleul buff, darkening toward tip." It is said 

 to be thus paler than its near relatives of the ornatus group, and 

 its skull is smaller than in any except Sorex tenellus and S. 

 nanus of Owens Valley, California, and Colorado, respectively. 

 Total length, 98 mm., tail, 41; hind foot, 12; length of skull, 

 15.2. 



This small shrew is regarded by Dr. H. H. T. Jackson (1928) 

 as a distinct species, though its relationship to S. tenellus is 

 doubtless close. For many years it was represented only by 

 the two specimens in the collection of the U. S. Biological 

 Survey. Dr. Jackson believed it was probably confined to the 

 White Mountains of California, "where it is seemingly rare 

 and may even be exterminated by the destruction of its habitat 

 through sheep grazing." More recently, however, Dr. William 

 H. Burt (1934) has discovered it in the Charleston Mountains 

 of southern Nevada, where he considers it common "along the 

 small streams at altitudes of 8,000 feet or above" up to 10,000 

 feet, not far from water. The possibility that grazing has 

 already much restricted its habitat in the White Mountains 

 makes its inclusion here excusable. 



Order CHIROPTERA: Bats 



The bats form a large complex order; they are the only 

 mammals that truly fly. There are two suborders : 



Megachiroptera, fruit bats or flying-foxes. There is a single 

 family, found in southern Asia, Africa, Australia, and many of 

 the oceanic islands. They are characterized by blunt cheek 

 teeth and a second claw in the expanded wing-hand. 



Microchiroptera, insectivorous bats (several are secondarily 

 fruit-eating or carnivorous and one family is specialized for a 

 diet of blood). Sixteen families are usually recognized, of 

 which six are restricted to the New World and two are com- 

 mon to both hemispheres. The New World families follow: 



(1) Noctilionidae, primitive bats, found in tropical America. 

 They are related to the Old World Rhinopomidae and Embal- 

 lonuridae. Two genera are recognized; neither is here con- 

 sidered endangered. 



(2) Phyllostomidae, New World leaf-nosed bats. These do 

 not appear to be closely related to any Old World group, but 



