OF WASHINGTON. 13 
colony, or* sleeping place, was tenanted by some eight or ten 
different species. Although he noticed a few 9 $ , most of the 
specimens observed were cT cT . Small bees were found in closed 
blossoms of the lace flower, or wild carrot (Daucus carota) , while 
bumble bees rested under the edges of certain flowers. Wasps 
belonging to the genus Ammophila held on to grass stems 
by their mandibles, the body extended straight and wings 
closely folded. Some other species use their mandibles in the 
same way, but Ammophila is the only insect which, in some 
cases, uses its mandibles exclusively for this purpose, the legs 
not touching the stem. 
Mr. Banks referred to his recent visit to the Museum of 
Comparative Zoology at Cambridge, Mass., where he made an 
examination of Hagen's collection of Neuropteroid insects and 
Emer ton's collection of spiders. Some of Keyserling's types 
of spiders, also, are deposited in the Museum. He stated that 
Hagen's collection has not been rearranged but is kept intact 
just as Hagen left it. This Mr. Banks considered most com- 
mendable and a policy which should be more generally followed. 
Mr. Caudell mentioned instances which have come under 
his observation of the mating of different species of Melanoplus, 
Sckistocerca, and other Orthoptera. The Morse collection of 
Acrididge, he stated, contains a fine series of intergrades. The 
subject of hybridization was discussed by Messrs. Piper and 
Gill, the latter stating that so-called new genera in fishes have 
been based upon hybrids between different genera. 
Dr. Dyar read the following paper: 
OUR PRESENT KNOWLEDGE OF NORTH AMERICAN 
CORETHRID LARVAE. 
BY HARRISON G. DYAR. 
Having discussed, in conversation with Mr. Coquillett, the 
relationships of the Diptera allied to the Culicidae, it seemed to 
us a more natural arrangement to separate the true mosquitoes 
into a distinct family on the character of the presence of the 
proboscis, and remove the non-biting forms, the old Coreth- 
ringe, placing them with the Dixidae as a second family, under 
the name Corethridse. In the larvae of this group the mouth 
brushes are somewhat developed, and in other characters they 
approach the true mosquitoes. 
