— 176 — 



t\-ouId not omit them altogether but admit them as visitors. In the 

 Florida fauna he thought it would be best to include all found there. 

 He was of the opinion that any difficulty might be obviated by writers of 

 Monographs stating. on their title-pages that they treated of the insects 

 inhabiting the Northern temperate region of the U. S. rather than "the 

 U. S. north of JMexico'' as is now customary. 



Mr. Howard believed it best to separate mere captures from faunal 

 lists which should be based on residence of a species, and inquired how 

 such species could be a disturbing element in monographic works. 



Mr. Schwarz replied that they represent groups of genera or species 

 which have their nearest allies in the semitropics but not in our fauna. 

 It is important to recognize them as belonging to a troj)ical fauna. Fauna! 

 limits are often very sharply drawn and we should exercise more care in 

 defining such limits. 



Mr. Smith stated that he agreed in the main with Mr. Schwarz. 

 There is a difference in the semitropical and north temperate fauna;, some 

 small part of our fauna belongs to semitropical but nearly all to the North 

 temperate. There is no distinction between the United Slates and Canada 

 but there is a very distinct difference between north temperate and semi- 

 tropical faunae. He would not exclude Mexican from American insects 

 when they belong to the north temperate fauna. He thought we should 

 define not the fauna of a political boundary but that of a zoological 

 boundary. 



Dr. Riley remarked that the trouble is there is no definite boundary. 

 The people of this country desire to study insects occurring in the country, 

 no matter what their relationship outside. Include them in our faunal 

 studies but indicate their relations. In short, do with them as ]\Ir. Schwarz 

 has done in making a special study of their limits. 



Mr. Osborn remarked that species of one fauna so lap over into the 

 region of another that it is difficult to draw- a line between zoological 

 regions. Intermediate forms may occupy nearly equal territory in con- 

 tiguous faunal regions. It is important that these intruding species 

 should be included, perhaps with special note, for the very purpose of 

 indicating their extreme limits. 



Dr. Riley suggested the practical question, should a resident of 

 Florida expect to find such species mentioned in a work on Florida in- 

 sects or must he search in foreign works for them. 



Dr. Peabody asked if the tropic of Cancer is a dead wall separating 

 north temperate from tropical forms. He believed fixed lines do not 

 exist in nature. 



Mr. Smith said in certain species limitation is fixed by food-plant 

 and that may be fixed by temperature as a wall. 



