COLLEMBOLA OF MINNESOTA 33 



8. a. Mucrones tridenticulate, no small apical tooth present. 



Neither entirely dark, nor with longitudinal markings. 

 Body covered with short hairs, interspersed with a few 

 longer ones. Post-antennal organ broadly elliptical. 

 Large claw witli one outer and one inner tooth. Length 

 2 to 5.5 mm. viridis, 68. 



b. Mucrones quadridenticulate. 9. 



9. a. Long pre-apical tooth, far over-reaching the apical, 



which is very minute. Short hairs on body interspersed 

 with long. Large claw with one outer and two inner 

 teeth; small claw with one inner tooth. Length 3.8 mm. 



catena, 69. 



b. Apical tooth of mucrones projecting at least as far as 

 pre-apical. 10. 



10. a. Dark blue, Abd. V and VI with a few long hairs. 



Apical mucronal tooth outstanding, projecting far distal 

 to preapical tooth. Two proximal teeth set nearly opposite 

 to each other and at right angles to the mucrones. 



caeruleatra, 70. 



b. Dorsal median dark stripe, hair entirely short. Apical 



tooth projecting little beyond pre-apical, proximal teeth 



set obliquely to mucrones. pointing distally. Length 



2.75 mm. palustris, 70. 



Genus Entomobrya Rondani 1861. 



This genus, formerly known as Degeeria, stands next to 

 isotoma, from which it is separated by the much greater length 

 of Abd. IV. In Entomobrya this segment is at least as long as 

 the three preceding taken together. The antennae are shorter 

 than the body. Each eyespot contains eight ocelli in all our 

 species ; and indeed in all the species excepting those which be- 

 long to the genus Sinella. The latter genus was erected for the 

 reception of those Entomobryas having but two ocelli on each 

 side of the head. The weight of authority today seems in favor 

 of relegating these species back to the genus Entomobrya, as 

 the number of ocelli alone is not thought sufficient to constitute 

 a generic difference. There is no postantennal organ. The body 

 is well covered with fine short hairs, besides which, on the an- 

 terior part of the body there are longer, clubbed ones ; and on 



