COLLEMBOLA OF MINNESOTA 51 



somewhat. A few long hairs are borne on the ventral side 

 of the dentes, but none clavate, or longer than the breadth of the 

 dentes itself. Mucrones short and stout, with a single notch on the 

 outer edge, and about five on the inner edge ; at the base, on the 

 dorsal side, is a notch extending part way around. The sub-anal 

 bristles are very much curved, and from them the species derives 

 its name; they are pinnate in form. Length, 1.25 mm. 



Not very common. Found only, so far, in low, dark woods, 

 on the bottom lands of the Mississippi, where it was taken under 

 chips and pieces of drift-wood. 



Sminthurus longisetis n. sp. 

 PI. Ill, Figs. 8-isb. 



A brownish-black species, indistinctly mottled with yellow. 

 Back and top of head set with strong, truncate bristles, nearly 

 straight, and pointing backward. Antennas very slender ex- 

 cepting Ant. I ; Ant. II as long as Ant. III. The antennal seg- 

 ments measure in the ratio 5: 14: 14: 19. Ant. IV is not dis- 

 tinctly ringed, but whorls of short hairs indicate where rings 

 would come. On Ant. II and III are a few stiff sense hairs, 

 about as long as three times the width of the antennae, and 

 standing out at right angles to those organs. The head bears 

 at its vertex a prominent tubercle, as in S. minnesotensis and 

 S. curvisetis. The eye-spots are dark yellow in color, and very 

 convex. Legs short and with very stout claws, the larger one 

 bearing a notch-like inner tooth. At the tip of the inferior claw 

 is borne a slender, simple hair, which projects about half its own 

 length beyond the tip of the larger claw. The tibia bears four 

 clavate hairs. Furcnla strong; manubrium as long as dentes 

 and mucrones taken together, and reaching back as far as the 

 tip of the anal segment when, extended. Dentes stout and some- 

 what tapering, each ramus bearing on its ventral side three long 

 sense hairs, set at almost right angles to the dentes. Mucrones 

 short and stout ; the outer edge nearly smooth, except for the 

 rounded scollop near the tip, the inner edge somewhat coarsely 

 serrate, a rounded tooth at the back running part way around 

 the base. The anal organs are deeply cleft and much curved. 

 Length, 1.8 mm. 



