Koford 271 Cynomys ludovicianus September 21, 1955 Scotts Bluff, Nebraska. Headed out, & conspicuous at a distance. I) Bemisquam habit Bgr), single-stalk habit Arm, & both prototolmen in faler an old meadow are very apparent (no prototole am another). II) 1941 invasion area near headquarters required crossing of gully 50yds. wide, 15' deep, but now vegetated most of distance. In this area much Sba near old burnours, & Aristida. Bgr'd area characterized by Stipa & Arm, the Bgr is 50% compass, some sites. Burnour sites conspicuous with Sba, white Malestis, Art. frig., Lautierieja, Lygodonia, Many Thonanyz wounds. I think it is probable So that stands Arm or Stipa canata as seen here could prevent establishment of migrating C.L. I believe that a stem density that makes it impossible for C.L. to walk without striking stems will prevent such establishment (but can walk into afforable condition adjacent). Stems must be seed "high, of course, as C.L. walks are closely grazed dense soon. September 22, 1955 Wind Cave Not' Park, S.Dak. Rain. Grass dry appearing now. Red-brown Androp. scop., stands out strongly on slope & hilllochus, but flattens over mostly Bromus in dense stand 1' tall. II) Esta Suter says he marked limits some trains with stakes years ago. Dogs that went out & dig new holes always old ones, & that later they came back in 4 abandoned autumn burnours. II) Visited Basin Flat colony in mid-afternoon. In arm to W. of road I counted 13. Two of these separate from rest (along foot of hills), 150yds. N. of hills + 50 yds. W. of road. These two at a round atop a large old mound 2' thick & 40' across. Bigird, covered mostly with Bda, but also Bgr, Arm, Aristida, & 5% weeds. Alongside