Mammals of the District of Columbia. 97 



Microtus pennsylvanicus. Meadow ]\Iice are probably the most 

 abundant mammals of the District. They press into the edge of the city 

 on all sides and even into the parks and grassy vacant lots. Several have 

 been caught in the Department of Agriculture grounds. Mr. Preble has 

 caught a large number on the Potomac flats, and I have myself taken 

 fully 100 close to the edges of the city. They are numerous along the 

 Rock Creek flats from Massachusetts Avenue bridge up through the 

 Zoological Park and fairly swarm along tlie Potomac and Anacostia 

 marshes. They also range to the tops of the highest hills wherever a 

 heavy growth of grass furnishes a good supply of food and sufficient 

 cover for their runways. A few are found in the woods, especially along 

 the edges of creeks, but open country, marshes, and grassy bottom lands 

 are their favorite haunts. 



Microtus pinetorum. Pine Mice are common, but less so and less 

 frequently taken than the meadow mice, which often occupy the same 

 ground. The generalization may be made {hnt it will not always hold) 

 that the meadow mice live in the fields, meadows, and oi)en country, 

 while the pine mice live in the woods and brush. The pine mice are 

 frequentl}^ caught in old fields and on open bottom land, but are foimd in 

 greatest abundance in brushy bottoms along creek flats. The narrow 

 flats along Rock Creek in the lower part of the Zoological Park are thickly 

 marked with their ridges and the little round holes that lead into the 

 burrows. Most of the traps that I set on this flat for moles caught only 

 pine mice, a large number of which were also caught in traps set along 

 the little creek in Woodley Park. A few were caught along Piney Bi-anch 

 and Broad Branch, and one near Fort Marcy, on the west side of the 

 Potomac. Mr. Green caught them on the flats between the canal and 

 Potomac, about a mile above Georgetown, and on a wooded knoll a quarter 

 of a mile below the west end of Long Bridge. 



Synaptomys cooperi. Cooper's Lemming-mouse. In 1888 Dr. Fisher 

 examined some pellets of long-eared owls from Munson Hill, Yii-ginia, 

 and among 176 small mammal skulls in these pellets were 3 skulls of 

 Synaptomys. Another skull was found in the stomach of a red-tailed hawk 

 killed at Sandy Springs, Maryland, March 24, 1890.* It was, of course, 

 impossible to know the exact localities where the hawks and owls pro- 

 cured these rare specimens. In February, 1896, I caught 4 Synaptomys 

 in a sphagnum swamp near Hyattsville, 5 miles northeast of the Capitol, 

 where their nests and runways are common in the damp, cool spliag- 

 num. No doubt more careful trapj^ing would have resulted in a greater 

 number of specimens. As the animals have been so long suspected and 

 so thoroughly trapped for in various places about the District, it is rea- 

 sonable to infer that they are restricted to these cold swamps. 



Zapus hudsonius. Jumping Mice have been taken on the west side 

 of the Potomac close to the city. Morris M. Green caught several at a 

 point a quarter of a mile below the west end of Long Bridge and about 



*A. K. Fisher: Hawks and Owls of the United States. Bulletin 3, 

 Div. of Ornithology and Mammalogy, 1893, pp. 59 and 141. 



