Oct., '04] ENTOMOLOGICAL NEWS. 277 



i. Abdomen bluish green ; malar space longer than broad ; stigma small 

 but distinct ; second recurrent nervure with a double curve 



(Chile) . albopilosa Spinola. 



Abdomen brilliant dark blue, shot with purple ; hair of thoracic dor- 

 sum entirely black ; malar space much broader than long ; 

 stigma small but distinct, second recurrent nervure only 

 slightly curved (Chile). 



cyaniventris Spinola (syn. of cyanescens Haliday). 



The following additional details will be useful : 

 C. ursina Sm. 9 . Columbia. Close to C. grisea. Malar 

 space very large, much longer than broad ; hair of head and 

 thorax black and grey mixed ; stigma small, piceous ; second 

 recurrent nervure with a strong double curve. 



C. nitida Sm., C. thoracica Sm., C. mandibularis Sm. ( ), 

 and C. pcrplcxa Sm., all have the malar space short, at least 

 twice as broad as long. C. grisea Sm., has it large, not greatly 

 broader than long. C. intricata Sm., has it fairly long, but 

 still much broader than long. 



Additional Dragonfly (Odonata) Records for 

 Western Pennsylvania. 



BY E. B. WILLIAMSON. 



The following list of dragonflies is based on a collection 

 from Sandy Lake, Mercer County, Pennsylvania, made by Dr. 

 D. A. Atkinson, to whom I am indebted for the specimens. 

 Dr. Atkinson writes me that "several coal mines drain into 

 Sandy Lake, and the water from these has killed off (or driven 

 away) all the fish and turtles. In adjoining swamps I took a 

 few turtles and a number of snakes. I saw a frog, Rana cat< s- 

 biana, catch and eat a small blue dragonfly {Enallagnia 

 hageni /)." 



" Man marks the earth with ruin," destroying native floras 

 and faunas, especially in mining, manufacturing and oil-pro- 

 ducing regions, and the captures of Odonates made by Dr. 

 Atkinson are here recorded in the belief that at some future 

 time, more than at present, they will be of value to the stu- 

 dent of geographical distribution. 



The dragonfly fauna changes quickly with changed envir- 



