236 Field Museum of Natural History — Zoology, Vol. XL 



So few specimens have been taken in Illinois that we know very 

 little as to its habits in the state. Thus far it has been taken only in 

 Hardin, Champaign, and Marion counties. The specimens recorded 

 by Wood as found dead near Urbana, Champaign Co., were "on a 

 low bluff overlooking a creek, in pasture land where there were stumps, 

 and scattered trees." (/. c, p. 56.) In southern Illinois, however, 

 they seem to prefer swampy localities, as do those which have been 

 taken in Missouri. 



Mr. A. H. Howell found this species common at Horseshoe Lake, 

 St. Charles County, Missouri. He says, "A large colony had occupied 

 a low marshy meadow close to the Mississippi River. At the time 

 of my visit the water in the river was very high, and the meadow was 

 overflowed to the depth of 12 to 18 inches. The mice had been driven 

 from their burrows by the high water, and were hiding as well as they 

 could on tussocks and under patches of floating debris. When dis- 

 turbed they ran rather slowly over the submerged vegetation and 

 swam freely, but were easily overtaken. Many had been killed by 

 dogs or other predatory animals, and I was able to get as many speci- 

 mens as I needed by catching them in my hands. The burrows in this 

 meadow were on little hillocks, the entrances near the top. Thus they 

 are probably dry except in times of very high water. The entrances are 

 perfectly open and not concealed under vegetation as is the habit of 

 Synaptomys cooperi in the eastern States. Well beaten runways 

 extended out from the burrows and under the dead vegetation." 

 {I.e., p. 30.) 



Mr. Howell secured a single specimen of Synaptomys in Illinois, 

 which he provisionally referred to this form. It was taken in an old 

 dry marsh at Odin, Marion Co. He states that it agrees with gossii 

 in color, but the skull is too young to be properly identified (/. c, p. 30). 



Specimens examined from Illinois and adjoining states: 

 Illinois — Rosiclare, Hardin Co., 11; (I. S. L.) (intermediate between 



gossii and cooperi) Urbana, Champaign Co., 2 (only one with skull). 

 Missouri — (B. S.) Horseshoe Lake, 6. 

 Iowa — (N. M.) Knoxville, i. 

 Indiana — (Not typical, intermediate between gossii and eooperi but 



averaging nearer cooperi) Bascom, 2 ; Mitchell, 2 ; Hebron, i ; Brook- 



ville, 1 = 6. 



