Hagen.] 250 [Feb. 3, 



rent ascending on the further side of the range, and therefore 

 reaching its crest at a relatively high temperature ; so that when 

 descending again as the Foehn, and warming at the more rapid 

 rate characteristic of clear air, it becomes much warmer than it 

 was at its starting point : this explanation was suggested in a 

 general way by Ebel early in this century and by Espy thirty 

 years ago, and has found its full confirmation by Hann and others. 

 A diagram was drawn to illustrate these processes, showing by 

 one set of curves the variation of temperature with height at differ- 

 ent seasons, and by other curves the adiabatic changes of temper- 

 ature in a mass of dry or moist, as ascending or descending air. 

 Detailed observations in our mountain regions are much needed 

 to define the occurrence of the Chinook winds with accuracy. 



Dr. S. Kneeland remarked on the habits of our winter ducks, 

 which every evening leave their feeding ground in our harbor and 

 disappear eastward. They probably go to the outer ledges for the 

 night to escape the persecution of gunners. 



General Meeting, Feb. 3, 1886. 

 The President, Mr. S. H. Scudder, in the chair. 

 The following papers were presented : 



MONOGRAPH OF THE HEMEROBID^l. 



BY DR. H. A. HAGEN. 



Part I. Nemopterid^e. 



The surprising discovery b} r M'Lachlan of a species of this fam- 

 ily in South America, and his valuable remarks on the other spe- 

 cies, have induced me to study the contents of the Cambridge 

 collection, and look over my notes collected since 1866, when I 

 published the "Hemerobidarum synopsis synonymica." 

 1. W. sinuata 01 i v. 



I have before me seven specimens from Turkey, coll. Charpen- 

 tier, labelled by him N. sinuata ; Balkan by Lederer ; Rumelia 

 coll. Winthem ; Syria, two by Lederer, coll. 1863 ; from Kellenisch, 

 Asia Minor, coll. Loew, the type mentioned by Dr. Schneider, Stett. 

 Ent. Zeitschr., vi, 153. Lucas, Ann. Soc. Ent. 1883, in, Bull., p. 116, 

 states that Abbe David found N. sinuata very common in N. Syria, 

 north from Antiochia. 



