372 rROVEEDIXGi-i OF THE XATfOXAL MUSEUM. vol.37. 



the purpose of this study was the preparation of a means of readily 

 identifying specimens, repeated examination of the individuals before 

 me has been disappointing in its failure to discover striking specific 

 characters, and I have been tempted to return the borrowed material 

 and not publish these notes at all. It is probable, however, that 

 unless some new interest is taken b}^ collectors in the North American 

 ^lacromias the present difficulties will confront students of North 

 American dragonflies for an indefinite period of time. In the hope of 

 awakening some interest in these beautiful insects I find an excuse for 

 the publication of this incomplete paper. 



I am indebted to the following persons for the loan of material: 

 Mr. C. C. Adams, Mr. C. S. Brimley, Dr. Philip P. Calvert (from his 

 collection and the collection of the Academy of Natural Science, Phil- 

 adelphia), ]\Ir. RoUa P. Currie (collection U. S. National Museum), 

 Mr. Samuel Henshaw (collection Museum of Comparative Zoology), 

 Prof. J. S. nine (collection Ohio State University), Mr. R. A. Mutt- 

 kowski (collection Milwaukee Public Museum), and Prof. E. M.Walker. 

 Unless otherwise indicated, specimens are in my collection. The 

 total number of specimens examinoil in the preparation of this paper 

 is 197 — 141 males, 56 females. Nearly one-half of this number is 

 Macromia ilUnoiensis. The wings of Azuma were photographed by 

 Newton Miller; the other wing photographs were made by Professor 

 Needham. 



MACROMIA T.ffiNIOLATA Rambur. 



Length of abdomen : Male, 56-61 mm.; average, 59; female, 57-61 

 mm.; average, 59.9. Length of front wing: Male, 50.5-56 mm.; 

 average, 54.1; female, 56-61 mm.; average, 58.3. Length of hind 

 wing: Male, 48-53.5 mm. ; average, 52.1 ; female, 53-59 mm. ; aver- 

 age, 55.6. Length of first tibia, male, 9 mm.; hind femur, male, 13 

 mm. Length of tibial keel in length of tibia, male: First tibia, ^; 

 middle tibia, \ to {. 



Antehumeral stripe present, extending about half or slightly less 

 across the mesepisternum. Latero-ventral metathoracic carina brown, 

 with or without a narrow yellow stripe anteriorly. Yellow ring on 

 abdominal segment 2 narrowly interrupted dorsally (interruption not 

 distinct in one male), not interrupted laterally. Costa dark colored. 



Afale. — Postclypeus clear greenish, labrum obscure dull yellow; 

 dorsal spots on frons minute to 1 mm. in diameter, lateral spots 

 wanting or indistinct. 



Abdominal spots on 3-6 small, rounded, separated dorsally, isolated 

 laterally from any inferior pale areas, about equal in size on all the 

 segments and occupying one-half or less the distance from the trans- 

 verse carina to the base of the segment; on 7 the large quadrangular 

 spot is separated by a narrow black ring from the base of the segment, 



