58 Bulletin No. 159 



plants, and to be found in some numbers under stones and 

 boards. In contrast with the habit of the adult these larvae 

 are still-hunters, lying in wait, often concealed, until suita- 

 ble prey comes within their reach, when suddenly they 

 thrust out a peculiar lower hp with strong jaws at its ex- 

 tremity and fasten upon it. They destroy in this way hosts 

 of small insects, Simulium probably among the rest, and 

 attack and sometimes do a good deal of mischief to very 

 young fish fry. 



The larvae of this order collected in Laurel River, Cum- 

 berland River, Straight Creek, and Clear Creek, represent 

 two main groups, one of which comprises rather slender 

 species (Represented by Fig. 45) with three long flat plates 

 for respiration at the hind end of the body. These are the 

 young of the damsel flies, very slender and rather small 

 gauzy- winged insects known to everybody from their dispo- 

 sition to alight on one's float or cork when fishing. The 

 second group lacks these plates, and is composed of larger 

 broader species (See Fig. 44) which respire by means of 

 gills placed on the walls of the hind portion of the digestive 

 tube. 



Species of Progomphus, Gomphus, Macromia, Calop- 

 teryx, etc., were collected among the rocks on which 

 Simulium larvae occurred. 



PLECTOPTERA (STONE FLIES). 



In every locality collected from, I found a few repre- 

 sentatives of this group of aquatic insects. The larvae were 

 associated with many examples of the group Ephemerida, 

 but not more than one of the stone fly larvae to a hundred 

 of the others was seen. They are flat insects with wide 

 heads, the thorax in three broad divisions, the antennae 

 many jointed and long, the abdomen terminating in two 

 long, tapering jointed stylets, much like the antennae in 

 structure. They are active predatory insects, feeding with 

 special relish upon gnat larvae, according to Miall. They 

 are found with Simulium in rapids, on the under sides of 

 rocks, which surfaces they quickly regain if permitted when 



