COLLEMBOLA OP THE FAMILY ISOTOMIDAE 53 



This variety with two knobbed hairs has been named clavipila by 

 Axelson (1903a; 1912). There is often present also a third tenent 

 hair, not mentioned by other writers, on the opposite side of the 

 tibiotarsus, above the iinguiculus; it is weak, like the second hair, 

 and may easily be overlooked. 



Remarks. — JMy North American material of this species agrees 

 with numerous examples sent to me from Finland by Linnaniemi 

 and from Germany by Schaffer. 



Proisotoma minuta is essentially a soil-frequenting species, occurring 

 often in large colonies, and occasionally in dense masses. In Europe 

 it has been taken under dead leaves, wood, cow manure, in heaps of 

 sawdust, under bark, under stones, on pools of fresh water, on the 

 seashore under seaweed or stones, in wells and cisterns, and under 

 flowerpots in dwelling houses or greenhouses. 



In regard to specimens from Red Hook, N. Y., sent to Dr. E. P. 

 Felt and referred to the writer for determination, Dr. Felt wrote: 

 "The large number sent, a teaspoonfnl or so of practically undiluted 

 insects, indicated that the species must have been enormously abun- 

 dant, probably as a result of an unusually prolonged moist spell. 

 They were on the ground and plants in and about a hotbed." 



The number of specim.ens that I received from Pennsylvania — also 

 indicated a similar abundance. 



Distribution.- — In Europe, Proisotoma minuta has been recorded 

 from Norway, Sweden, Finland, Hungary, Russia, Siberia, German7, 

 Ital}^, Scotland, and England. 



Massachusetts: Cambridge, May 24, great quantities in a greenhouse, E. L. 



Mark. 

 Connecticut: Warehouse Point, June 9, from soil of tobacco field, G. S. Phelps, 



from W. E. Britton (Connecticut Agricultural Experiment Station). 

 Pennsylvania: From H. A. Surface (Pennsylvania State College). Bustleton, 



July, C. A. Thomas. 

 New York: Nassau County, April 25, in masses in a greenhouse, C. R. Crosby 



(New York State Museum). Red Hook, June 7, from E. P. Felt (New York 



State Museum). Westport, May 18, immense numbers, F. C. Smith. 

 Illinois: Champaign, March 24. Chicago, November 7, P. S. Welch. Homer, 



March 31, April 5, 7, 11, 13. Oakwood, April 20, T. H. Prison (IlUnois 



State Natural History Survey). 

 Iowa: Ames, March 28, April 3, J. E. Guthrie. 

 Kansas: Dodge City, January 6, in egg capsules of grasshoppers, P. S. Welch. 



Manhattan, November 12, in termite nest in a fencepost, P. S. Welch. 

 Louisiana: Baton Rouge, abundant, H. A. Morgan; March 9, abundant in 



cane trash, C. L. Stracener. Tallulah, April 17, abundant in damp spots 



under loose bark of a dead black locust tree. 

 Texas: Waxahachie, February 6, thousands, M. C. Tanquary. 

 California: Claremont-Laguna region, G. A. Bacon. 

 Canada: Banff, Alberta, July 13, on surface of wooded swampy pool at base 



of Rundle Mountain; July 24, on soil in cold frame growing lettuce, C. G. 



Hewitt. St. Andrews, New Brunswick, May 26, from C. Macnamara 



(National Collection, Ottawa). 



