100 



ANIMAL COMMUNITIES OF STREAMS 



REPRESENTATIVES OF THE POOL COMMUNITY 



FIG. 56. A long-legged spider taken from a stone out of water in a stream 

 (Tetragnatha grallator); twice natural size (original). FIG. 57. Outside of shell of a 

 small mussel from Hickory Creek (Alasmidonta cdceola); natural size (original). 

 FIG. 58. Inside of the same. FIG. 59. Inside of shell of mussel from Hickory Creek 

 (A nodontoides ferussacianus, subspecies subcylindraceus Lea); natural size (original). 

 FIG. 60. Outside of the same. FIG. 61. A snail from the still water of Thorn Creek 

 (Campeloma subsolidum) ; natural size (original). FIG. 62. A snail from the still 

 water of Hickory Creek (Planorbis bicarinatus), seen from the left; natural size 

 (original). FIG. 63. The same seen from the right. 



