126 Key to Families of North American Insects. 



Sessfle, broadly attached. 



Seta (-tae), a bristle or filament. 



Setaceous, bristle-like, slender. 



Sinuous, S-shaped, winding back and forth. 



Small-crossvein, a short crossvein extending from the base of the discal cell to the 

 fifth posterior cell (PI. 12, fig. 258, p. c. v.). 



Spatulate, broad at tip, narrowed at base. 



Spinulated, furnished with very small spines. 



Spiracles, breathing pores along the sides of the body. 



Spurs, movable spines, usually two, at the end of the tibiee. 



Spurious vein, an extra vein crossing the anterior crossvein (Diptera) (PI. 12, fig. 

 281). 



Squamopygidium, a plate formed by the fusion of several apical abdominal seg- 

 ments (Dermaptera). 



Sternite, the ventral piece of each abdominal segment. 



Sternopleural bristles, the bristles on the triangular side piece between the front and 

 middle coxae (Diptera) (PI. 13, fig. 303, stp.). 



Stigma, a thickening on the costal border of the wings. 



Stridulating, making a chirping or creaking noise. 



Style, a bristle-like process terminating the antennae, thicker than the arista (Dip- 

 tera). 



Styles, short slender appendages on the underside of the abdomen (Thysanura). 



Stylifonn, drawn out as a slender stiff process. 



Subantennal grooves, a groove or grooves in the middle of the face (Diptera) . 



Subc6sta, the second of the principal veins of the wings. 



Submedian cell, a long cell near the base of the wing (Hymenoptera) (PL 3, figs. 

 36, 37, 48, SM.). 



Submentum, the basal part of the mentum. 



Sulcate, grooved or furrowed. 



Supraanal plate, a dorsal piece terminating the abdomen. 



Suture, the line separating the pieces of the body wall. 



Tarsus (-si), the foot, the jointed portion of the leg beyond the tibia. 



Tegmen (-mina), the toughened upper wings of grasshoppers, etc. 



Tegula (-Ise), a small convex plate over the root of the fore wings (Hymenoptera) 

 (PI. 4, figs. 68, 73, T.). 



Telson, the last abdominal segment. 



Tergite, the dorsal piece of an abdominal segment. 



Thdrax, the second of the main divisions of the insect body, between the head and 

 the abdomen, bearing the legs and wings. 



Tibia (-i), the shin-joint of the leg, between the femur and the tarsus. 



Triangle, a small triangular cell near the base of the wing (Odonata). 



Trochanter, the small joint of the leg between the coxa and the femur. 



Trochantin, a small piece on the outer side of the coxa (Coleoptera). 



Truncate, ending squarely, blunt. 



Venation, the course of the veins or rod-like thickenings of the wings. 



Ventral, pertaining to the underside of the body. 



