30 COLLEMBOLA OF MINNESOTA 



4. a. — Antennre 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 bide tbe 



bead. Genus Lepidocyrtus, 36. 



b. — Pronotum not produced forwards. 



Genus Seira, 35. 



Genus Orchesella Templeton 1835. 



Orcbesella is especially interesting as tbe only collembolan 

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

 ratber large for Collembola, and nearly all species of tbe genus 

 are quite strikingly colored. I have generally taken tbem singly 

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

 very abundant after a rain on tbe 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 witb 

 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 Orchesei-la. 



1. a — Body yellow mottled witb dark blue. 2. 



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

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

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

 of tbe 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 tbe width of Ant. II. 

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



zebra, 61. 



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



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



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



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



