104 AMERICAN HYMENOPTERA. 



from a condition where all of the median and most of the 

 radial and cubital cells are of this shade, to a state where it 

 is only present as a narrow band along the basal vein, while 

 in the radial and cubital cells the bases or even the whole 

 cubital cell may be hyaline. In the types of A. atriventris 

 the median and radial cells are fuliginous ; in the type of 

 Tipulophion gigas the radial, base of the cubital and the me- 

 dian except a median longitudinal hyaline stripe, are fuligin- 

 ous ; in the type of T. ruHthorax the fuliginous occupies the 

 radial cell, except the base, and forms a long band along the 

 basal vein. T. spectabilis is related to atriventris, for they 

 agree in size and color of the body, but in the former the 

 eyes are small and narrow, the metathorax finely striate, not 

 coarsely reticulate and the whole apex of the wing is fuli- 

 ginous. 



An examination of the type of A. thoracicus satisfies me 

 that it. is a synonym of A. atriventris Cress. ; the description 

 of Tipulophion gigas and the descriptions and colored plates 

 of Macrophion ornatus Szep. and Thyreodon ruHthorax Cam. 

 show that they are also synonymous. Mr. W. A. Schulz 

 states that Macrophion fenestratus Szep. is the hitherto un- 

 known male of A. atriventris {T. ru/ithorax) , but this is evi- 

 dently a mistake, for Macrophion fenestratus is synonymous 

 with Athyreodon fenestratus Tasch. 



Distribution. — This species apparently ranges from Mexico 

 to southern Brazil. It has been reported from Orizaba, 

 Mexico ; Honduras ; Costa Rica, Volcan de Chiriqui at 7,000 

 feet, etc. ; Bugaba, Panama, 8 to 1,500 feet ; Brazil, Orobo 

 in Bahia, Theresapolis in Santa Catharina, Rio de Janeiro, 

 Rio Grande do Sul. 



Nothing is recorded of the life history, habits or hosts. 



Location of specimens. — American Entomological Society, 

 type 9 , No. 71, Mexico. Massachusetts Agricultural Col- 

 lege, homotype, 9 , Chiriqui. U. S. National Museum, type of 

 thoracicus K^\xn\. British Museum.* Munich State Museum, 



* The type of Thyreodon rufithorax Cam. is not in the British Mu- 

 seum, and may have been retained by Mr. Cameron or deposited in 

 the Vienna Museum with some of his other material. 



