J. C. HUTSON 203 



THE NORTH AMERICAN SPECIES OF THE GENUS 

 SCELIPHRON I HYMENOPTERA) 



by j. c. hutson 



Introduction 



This paper has been prepared by the writer in the Entomologi- 

 cal laboratory of the Massachusetts Agricultural College, Amherst, 

 as a part of a thesis for the Degree of Doctor of Philosophy. 

 He here desires to express his debt of gratitude to Dr. H. T. Fernald 

 for his valuable suggestions and kindly interest at all times during 

 the progress of the work, and for his trouble in securing material 

 from many public and private collections in the United States; 

 to Dr. G. C. Crampton for his ready help in the anatomical 

 portion of the paper; and to Mr. Daniel G. Tower whose pre- 

 liminary notes on these insects were at the disposal of the WTiter, 

 and were of no small assistance. The writer is also under great 

 obligations for opportunities to study material from the United 

 States National Museum, the American Entomological Society 

 at Philadelphia, the Brooklyn Museum, and the New Hampshire 

 State College, which had been loaned to Professor Fernald 

 through the kindness of those in charge of these collections, and 

 also from Professor Herbert Osborn, Dr. J. C. Bradley and many 

 others, which were obtained in a similar way. 



General Characters 

 The insects of the genus Sceliphron of the subfamily Sceli- 

 phroninae found in North America are of medium to small size, 

 varying from half an inch to an inch even within the same species. 

 The wings are large in proportion to the somewhat slender body 

 and the legs are long, especially the hinder pair. The surface of 

 the body is almost completely covered with punctures varying 

 in size and proximity to each other, and with hairs differing in 

 length and density on various parts of the body. It will be 

 noticed that the nature of the punctation bears a close relation 

 to the size and distribution of the hairs, in that each puncture 

 usually has its corresponding hair, though some of these are 



TRANS. AM. ENT. SOC, XLV. 



