140 Bulletin Wisconsin Natural History Society. [Vol. 8, No. 3. 



teriorly. Nape and sides of neck silver grey; this color prolonged bark- 

 ward above the shoulder in the form of stripes which are sometimes 

 faintly traceable to the root of the tail, though usually ending about 

 the middle of the body. Ears black outside, grayish or faintly rusty 

 inside, and along posterior border. Top of head bister, slightly dusky 

 above orbits, which are encirccled by white. Sides of head grayish, 

 mixed with yellowish brown. The tail, which is less bushy and shortsr 

 than in O, grammurus, is yellowish gray, the lateral hairs thrice 

 annulated with black. Feet yellowish gray. Under surface of the holy 

 grayish white. The interscapular region is often blackish, more or 

 less vermiculated with pale annuli. Length. 410 mm.: tail vertebrae, 

 170; hind foot, 55; ear above crown. 21 : car above not di. :37 ; lensrth 

 of head. 62: skull. 57 by 34 mm. 



They live in colonies and migrate twice a year, taking up their 

 habitation in the high hills during the wet weather, where they 

 breed and where the young are born, and descending to the culti- 

 vated lands in the valleys in the spring time. They dig holes in 

 the ground, the burrows being constructed in quite a systematic 

 manner. There are usually several entrances, the angle of the 

 tunnel depending very largely upon the character of the soil in 

 which it is sunk. ( )ften it is found that the tunnel forks, one 

 branch going to a store house and the other to the nest. In this 

 store house are found various seeds, the conns of a weed which 

 grows in great abundance in that region, acorns, beans and the pits 

 of fruit, such as peaches and prunes. The nest is lined with pieces 

 of bark, straw and similar debris, and is usually alive with tieas. 

 Extending from the nest there is frequently found a vertical shaft 

 connecting with the surface of the ground. This is believed to be 

 built for the purpose of ventilation, although sometimes it is util- 

 ized for an avenue of escape. The earth dislodged in digging the 

 burrow is usually piled in a mound in front of the hole, and there 

 are usually seen in the neighborhood of the home burrow small. 

 incomplete tunnels which are really hiding holes into which squir- 

 rels drop when pursued. Some of the warrens are verv extensive 

 and contain several hundred squirrels. Frequently an entire hill- 

 side is undermined, its entire face being dotted with little mounds 

 of earth or soft limestone thrown out in making the excavations. 



Squirrels breed once a year, the exact time depending very 

 largely upon climatic conditions. The young are usually born in 



