30 COLLEMBOLA OF MINNESOTA 



4. a. Antennae ringed on III and IV. 



Genus Tomocerus, 35. 

 b. No Antennal segments ringed. 5. 



5. a. Eyes absent. Genus Cyphodeirus, 35. 

 b. Eyes present. 6. 



6. a. Pronotum projecting forward so as to partly hide the 



head. Genus Lepidocyrtus, 36. 



b. Pronotum not produced forwards. 



Genus Seira, 35. 



Genus Orchesella Templeton 1835. 



Orchesella is especially interesting as the only collembolan 

 genus with six-segmented antennae. In size all our species are 

 rather large for Collembola, and nearly all species of the genus 

 are quite strikingly colored. I have generally taken them singly 

 or in small numbers under stones, etc., but once found them 

 very abundant after a rain on the tops of stumps. They are active 

 in their movements. Each eyepatch has six ocelli, and I believe 

 there are no cases of degeneration from this number throughout 

 the genus. The body is without scales but well covered with 

 hairs, the larger of which are clubbed. 



Three species have been taken in Minnesota, of which at 

 least two are new. 



KEY TO THE GENUS ORCHESELLA. 



1. a Body yellow mottled with dark blue. 2. 



b. Body white or almost colorless, with no dark markings. 

 Ant. Ill with a dark ring at distal end, longer than the 

 width of Ant. II. Head with a black median spot front 

 of the eyes. albosa, 61. 



2. a. Antennae short, not so long as the distance from ceph- 



alic end of head to Abd. IV. Ant. Ill colorless, short, 

 its length being not greater than the width of Ant. II. 

 Ant. II, IV and V with dark distal rings. 



zebra, 61. 



b. Antennae reaching as far as middle of Abd. IV. Ant. II, 

 III and IV with black distal rings. Ant. Ill much longer 

 than II is wide. Sides of head with dark lateral stripes 

 which include the eyespots.. (n. sp. ?) 



