COLLEMBOLA OF MINNESOTA 35 



and VI. Head yellow with small median black spot be- 

 fore the eyes. spectabilis, 77. 

 b. — Cross-bands less clearly marked. Some dark color on 

 Th. II and III. The band on Abd. IV usually broken. 

 Head commonly with anchor-shaped marking between 

 the eyes. multifasciata, 77. 



Genus Tomocerus Xicolet 1841. 

 The genus Tomocerus seems so distinct from the other 

 members of the family Entomobryidse that some good author- 

 ities recognize a family Tomoceridge. For convenience sake, 

 however, we let it remain where it is usually placed. The mere 

 fact that Tomocerus is scaled should not receive too much stress 

 in determining its relationships to other scaled genera, as its 

 scales are quite markedly different from those of Lepidocyrtus, 

 Seira, etc. The body is long and somewhat cylindrical in form, 

 and is heavily mailed with scales which have a leaden, semi-me- 

 tallic lustre. The long antennae have, like those of Papirius, a 

 short apical segment. The third and fourth segments are 

 whorled with short hairs and are very flexible. This genus re- 

 sembles Orchesella in having but twelve ocelli. The mucrones 

 is large and long and differs in form from all others excepting 

 a few closely allied genera, which are not represented in our 

 fauna. Another striking peculiarity is the presence of sharp 

 spines on the inner edges of the dentes. 



Key to the Genus Tomocerus. 

 Spines on dentes about 7 or 8. Mucrones with the large, spur- 

 like tooth somewhat removed from the base. 



arcticus, 79. 



Spines on dentes about 12 or 16. Mucrones with the large, 



spur-like tooth close to base on inner edge, and a smaller 



one opposite it on outer edge. niger, 80. 



Genus Cyphodeirus Nicolet 1841. 

 There is but one species of this genus known here, so far ; 

 and it is the type species upon which the genus was founded. 

 It is essentially merely a white, eyeless Entomobrya with scales. 



albinus, 82. 

 Genus Seira Lubbock 1869. 

 This is another scaled genus of the Entomobrya group and 



