WELCH] WATER IXSECTS 181 



face is sometimes honey-combed in appearance, at other time-^ 

 composed of large ridges and furrows running irregularly up 

 and down. This peculiar top is called the cap, but is very 

 different from the caps of those we discussed at first. This 

 cap is buff, or dirty-straw-color, but becomes brownish as it 

 becomes older. The "Morels" are perhaps the most delicious 

 mushrooms that we have, and the first dish of them in the early 

 spring is as satisfactory to the mushroom-lover as is the first 

 blue-bird to the bird-lover. 



So now let us get ready our baskets and paper and boxes, for 

 soon the mushroom-season will be here and we can then make 

 a beginning at the study of this wonderland about us. with which 

 so many of us are scarcely acquainted. 



University of Michigan. 



The Insect Life of Pond and Stream 



P.\UL S. Welch. 



University of Illinois. 



Part II. 



The following key is intended to provide for the young col- 

 lector a simple means of identifying the common insects of ponds 

 and streams. 



With fully developed wings. (Some adult Water Striders and Marsh 

 Treaders are wingless : the wingless adult Water Strider usually has an 

 abdomen about as long as the thorax while the abdomen of the young is 

 much shorter ; the wingless adult Marsh Treader has a rigid body and 

 three-jointed tarsi while the young has a very soft body and one-jointed 

 tarsi.) I. 



IMMATURE IXSECTS ( LARV.\E AXD XYMPHs). 



Without fully developed wings. II. 



I. Adult insects. 



A. Insects living on the surface of the water. 



1. Insects with narrow dark bodies and long legs. 



o. Second and third pairs of legs longer than the body : head much 

 shorter than the thorax; movements quick and rather jerky. 



W^\TER Striders (Fig. 6). 



b. All of the legs shorter than the body; head as long as the thorax, 

 movements slow and never jerky. ^Iarsh Treaders (Fig. 7). 



2. Insects with oval black bodies : second and third pairs of legs very 

 short ; the first pair much longer ; movements often rapid and con- 

 fused. Whirligig Beetles (Fig. 8). 



B. Insects living under the surface of the water; are free swimming, 

 and are often seen hanging at the surface. 



