NO. 1928. DRAGON FLIES OF THE CUMBERLAND VALLEY— WILSON. 197 



28. HET^RINA TRICOLOR (Burmeister). 



This species first appeared at Celina, Tennessee, a little way below 

 the State line. It then rapidly increased in numbers and gradually 

 replaced americana, becoming the most common agrionine of the 

 lower portions of the river. 



It does not assemble in such large numbers as americana, and is 

 much more difficult to capture, but othenvise is almost identical in 

 its habits, and it frequents similarly the bushes along shallow rocky 

 ripples. It is a southern species and so is found on the lower portions 

 of the river among the lowlands. 



29. LESTES RECTANGULARIS (Say). 



The only species of the genus Lestes seen during the season was 

 captured on the shore of the small pond at Indian Creek Landing. 

 Both sexes were found in the dense underbrush on the shores, which 

 they seemed to prefer. 



30. ARGIA MOESTA PUTRIDA (Hagen). 



This is one of the three common species of Argia found everywhere 

 along the entire length of the river and on such of its tributaries as 

 were visited. It does not occur in as great numbers as the following 

 species, and is not so conspicuous in consequence of the lack of 

 blue at the tip of the abdomen. • 



But it is much like them in habits and frequents sunny places on 

 the river bank, usually alighting on the ground, on sticks, or on 

 stones. The younger females are pale brown, in such contrast to 

 the blue head and thorax of the fully matured adult that they look 

 like a different species. 



31. ARGIA APICALIS (Say). 



This is by far the most common damselfly on the river, and during 

 the whole season it was found in great numbers wherever the Odonata 

 were hunted. It was as abundant on the upper river among the 

 mountains as farther down in the lowlands. 



It seems to prefer a floating chip or a board at the level of the water 

 for oyiposition. Around such places the pairs congregate, the 

 females grasping the edge of the chip and thrusting their abdomens 

 as far as possible beneath the water, the males holding themselves 

 erect and perfectly straight above the neck of the female. Often the 

 chip is covered so completely that there is not room for even one 

 more couple. It then looks as if it were covered with a dense growth 

 of moss, having spots of bright blue on every stem. This species was 

 not seen to submerge itself while ovipositing as is frequently done by 

 the preceding species. 



32. ARGIA TIBIALIS (Rambur). 



Not as abundant as apicalis but occurring in about the same 

 numbers as putrida. The three were found everywhere together, 

 but tibialis seemed to prefer vegetation more than the other two, 

 and did not stick so closely to the open sunny spots. The fact that 



