40 ' proce;edings Manchester institute 



fittest under the stress of extreme conditions. A similar state of 

 things was observed along the channel of the brook which, in 

 all but extremely dry seasons, flows from Stevens' Pond, and 

 also along the dry course of the brook that crosses the road 

 near Massabesic. In each case the nymphs were living, not in 

 water, but in very moist mud, and it is probable that cannibalism 

 had quite as much to do with the reduction of their numbers as 

 did the failure of their water supplj'. 



The drought that prevailed in the vicinity of Manchester dur- 

 ing the summer of 1900 interfered seriously with the work of 

 increasing the Institute's collection. Eight additional species 

 of Anisoptera were secured, however, and the females of two 

 species of which the Institute already possessed the males. The 

 additions are as follows : 



Sub-Family Gromphiiite. 



Tacliopterix Selys. 



Tachopterix thoreyi Hagen. 

 Calvert, p. 241. 



These Dragonflies were flying in considerable numbers on the 

 sandy pine plains near Cohas Brook, on June 5, and two speci- 

 mens were secured on the River Road North June 8. Calvert 

 had not seen the female when he compiled his Catalogue, and 

 he repeats the description, " Vulvar laminae reaching base of 

 appendages." In the specimens at hand, the vulvar laminae 

 nearly reach the apex of the appendages. Otherwise, the de- 

 scription fully corresponds. 



Ophiogomplius Selys. 



Opliiogoiiiplius rupinsuleiisis Walsh. 

 Calvert, p. 242. 



Not abundant, and seemingly restricted in this localit}'^ to Co- 

 has Brook. 



Croniplius I^each. 



Gomplius abbreviatus Hagen. 

 Calvert, p. 243. 



