AS PEO les ade 
NORTH AMERICAN HENICOCEPHALIDAE.— PLATE I. 
BY 0. A. JOHANNSEN, ITHACA, N. Y. 
On the evening of July 5th while walking in my garden on Cornell Heights, 
Ithaca, N. Y., I noticed a swarm of small insects hovering in the air about 6 feet 
above the ground. From their manner of flight I supposed that they were Chirono- 
mids but was surprised to find that they were small Hemipterous insects belonging 
to the strange family Henicocephalidae. During the days which followed until the 
last week in August I never failed to find these insects in small swarms flying in the 
sunlight in the same locality and at about the same hour (i. e. from 5 p. M. until after 
sundown). Of their further habits I could learn nothing, nor did I find them at any 
other time of day. In looking over the literature but few references to North Ameri- 
can species were found. In the Lethierry and Severin catalogue twelve species are 
recorded from the world, of which two are from the United States and one from St. 
Vincent Isl., West Indies. In Biologia Centrali-Americana Champion described five 
species from Central America. ‘The two species from the United States, H. formicina 
and H. culicis, were described by Uhler in the Transactions of the Maryland Academy 
Science for 1892; the latter is redescribed by Ashmead in Proceedings of the Ento- 
mological Society of Washington in 1892 and quite recently recorded in the same 
periodical by Mr. F. Knab, from Mexico. As Uhler’s descriptions are rather inacces- 
sible to many American Entomologists I may be pardoned for giving here description 
and figures of H. culicis as well as the diagnosis of H. formicina and a table including 
also the Central American and West Indian forms. he variation which exists in 
the wing venation, the segmentation of the tarsus, the tarsal claws, etc., in the different 
species has given occasion for the erection of several genera. As hemipterists are by 
no means agreed as to the classification no attempt will here be made to subdivide 
the American forms into genera. 
