66 Annals Entomological Society of America  [Vol. XIV, 
corresponding adults do, and the clues obtained from an 
examination of the larval structures have amply justified the 
time spent in their study. 
Dr. F. C. Craighead has very generously permitted me to 
incorporate his observations on the musculature of the mouth- 
parts of an adult and larval Corydalis in this paper, and Figures 
11 and 14 of Plate III were drawn by him. Since the advance 
information which he has kindly permitted me to use, has not 
yet been published by him, I would emphasize the fact that the 
statements concerning the musculature of the mouthparts 
quoted in this paper should be accredited to him, as is indicated: 
where such quotations have been made in the following 
discussion. 
Through the kindness of Mr. Nathan Banks, I was able to 
examine a number of interesting insects in the Harvard Museum, 
and many of the drawings of the heads of Neuroptera were 
made from this material. Since the specimens were dried, 
however, it was not always possible to see all of the parts 
very clearly, and many of the drawings from this source are 
therefore rather diagrammatic. I am also indebted to Dr. 
Edna Mosher for the loan of a Hepzalis larva, to Dr. Cornelius 
Betten for the identification of the trichopterous larve here 
figured, and to Dr. Needham and Dr. Tillyard for some 
extremely interesting and valuable neuropterous larve. 
The principal papers dealing with the mouthparts and head 
structures of insects in general are those of Packard, 1882-1898; 
Chatin, 1884-1897; Waterhouse, 1895; Kellogg, 1902-1904; 
Comstock and Kochi, 1902; Verhoeff, 1904; Berlese, 1909; 
Crampton, 1916-1917, and Yuasa, 1920. Hosford, 1918, has 
also treated of the head structures of insects in general; but 
her paper is practically a review of Comstock’s work. Peterson, 
1916, has recently written a fine paper on the head structures 
of Diptera, comparing them with the head structures of 
Orthoptera; but unfortunately he did not make a study of 
intermediate forms connecting such primitive types as the 
Orthoptera with such highly specialized types as the Diptera, 
with the result that certain of his interpretations of the parts 
in Diptera are quite wrong, and other investigators such as 
Wesche, who have attempted to compare the structures of 
Diptera directly with those of Orthoptera, have fallen into the 
same error. 
