COLLEMBOLA OF MINNESOTA 45 



middle of the anal tubercle ; dentes sub-equal in length to the 

 manubrium ; mucrones one-third the length of dentes, simple, 

 pointed, with a slight hook at apex, with a high power appear- 

 ing very finely serrate. Length, I mm. Habitat: Ithaca, N. Y. 

 Under pieces of wood in a plant jar in the University Insectary." 



My specimens agree pretty closely with the foregoing in 

 most particulars, though I have failed to find any denticle on the 

 larger claw, and Ant. I is invariably yellow. The mucrones is 

 the same as in aureus, but the claws differ slightly from that 

 species. The claws of the second and third pairs are alike, but 

 the inferior claw of the first pair becomes narrower and has no 

 distinct inner denticle. The antennae are like those of niger, 

 fig. 18, having Ant. Ill plumper than in aureus. 



Taken only in the University greenhouse, where the spe- 

 cies is common in empty, inverted flower pots, under loosely 

 lying boards, etc. 



Though so minute, the species is readily identified even with 

 the unaided eye, from the strongly contrasting bright yellow 

 and inky black, which are seen rather less plainly in the young, 

 as their black is less intense. The yellow spot on the anal 

 tubercle is so large as to be seen at the sides of the tubercle from 

 a dorsal view. The positions of the ocelli are shown in fig. 12. 



The sub-anal papillae are rather stout, and bear a flattened 

 bristle of the same form as in 4-maculatus, figs, na and lib. 



Sminthurus quadrimaculatus Ryder. 



PI. V, Figs. loa, lob. 

 1878. Smynthurus quadrimaculata. Ryder, Proc. Acad. Nat. Sci. Phila. p. 



335 and figure. 

 1892. Smynthurus 6-maculata. Harvey, Ent. News. III. pp. 169-170. fig. 



Ryder describes the species as follows: "Dark brown, nearly 

 black on the sides ; median dorsal and ventral surfaces lighter ; 

 spring and middle of legs still more pale. Its distinguishing 

 character consists in the two pure white spots, low down on 

 each side of the abdomen, the posterior ones larger than the an- 

 terior by one-third to one-half, are arranged, when the back of 

 the animal is viewed from above, in an equilateral quadrangle. 

 The surrounding dark color immediately bordering the white 

 spots is intense, but becomes paler more remote from them in 



