1922] Otanes: Head and Mouth-Parts of Mecoptera 311 



specimens not obtainable locally, and I also wish to express my 

 thanks to the following gentlemen who very kindly donated 

 specimens: Dr. J. Chester Brodley, of Cornell University, for 

 Boreus nivoriundus; Professor Arthur L. Lovett, of the Oregon 

 Agricultural College, for Panorpodes oregonensis; Professor 

 FrankHn Sherman, Jr., of Raleigh, North Carolina, for Panor- 

 podes carolinensis; and Mr. Nathan Banks, of the Museum of 

 Comparative Zoology, for specimens of Apterohittacus apterus 

 and Merope tuber. My thanks are also due to Professor S. A. 

 Forbes and Dr. C. P. Alexander for specimens of Bittacus stri- 

 gosiis from the collections of the Illinois State Natural History 

 Survey and lastly to Dr. J. W. Folsom, for specimens of Boreus 

 nivoriundus, sent to him by Mr. Chas. Macnamara, of Arnprior, 

 Ontario, Canada, and for certain references. I wish also to 

 acknowledge the permission given by Dr. MacGillivray to use 

 his terminology, which will be embodied in a book on insect 

 morphology soon to be published. 



METHODS. 



The specimens of the head of the different species were 

 treated for a few minutes with a five per cent solution of hot 

 potassium hydroxide. Before being examined they were 

 washed with distilled water and then transferred to 70% 

 alcohol. All dissections and examination were made in alcohol 

 under a binocular microscope. Parts with minute details were 

 mounted temporatily on slides and studied under a compound 

 microscope. An ocular eyepiece micrometer ruled in squares 

 proved helpful in getting the proportions for the drawings. 



FIXED PARTS OF THE HEAD. 



The order Mecoptera is referred to by taxonomists as having the 

 head prolonged into a trunk-like beak at the end of which are located 

 the biting mouth-parts. An examination of the head of the various 

 species studied shows that Panorpodes (Figs. 1, 17, 27) does not conform 

 to this characterization of the order. It is very much orthopteran 

 in form and is the most generalized of all the genera studied and has 

 been taken as the type. Fanorpa (Figs. 10, 24, 31) and Boreus (Figs. 

 14, 26, 32) are the only genera that possess a trunk-like beak and are 

 the most specialized, Boreus being more so than Panorpa. Bittacus 

 (Figs. 3, 19, 28), Aptero-bittacus (Figs. 5, 23, 29) and Merope (Figs. 

 7, 25, 30) are intermediate in form. It should be mentioned, however, 

 that specialization is not monopolized by either Boreus or Panorpa. 

 Merope, for example, is without ocelli and in this respect is more highly 

 specialized than either Boreus or Panorpa. 



