CONTENTS 



351 



Phytoptus phlccocoptet of Europe, 460. Had been previously received from New York 

 by Dr. Riley, 460. Many gall mites doubtless remain to be discovered, 450. Fourteen 

 U. 8. species have been indicated, 460 The list of Osborn and Underwo )d, 460. The 

 number of American Phytoptus galls in the Museum of Comparative Zoology at Cam- 

 bridge, Mass., 460. The number known from North America, 450. Their distribution 

 in genera and families, 460. t • 



APPENDIX 461 



(A) THE SCORPIO N-FLIES 463 



Their habitat, 463. Economic relations, 453. Predaceous in their larval stage, 463. 

 Panorpa probably not injurious, 463. Panorpa and Bittacus separated by some writers 

 from the Neuroptera and assigned to the Mecoptera, 463. Characteristic features of 

 the Mecoptera, 453. Venation of Panorpa rufescens illustrated, 463. Why Panorpa Is 

 known as a Scorpion-fly, 464. Bittacus also placed among the Scorpion- flies, 464. 

 Little formerly known of the life-histories of these flies, 464. Brauer's studies of them, 

 464. Nothing published on the habits of the American spacies, 464. Studies at Cornell 

 University, 464. 



Panorpa rtfescbns 464 



The most common species at Ithaca, 464. P. maculosa abundant on the shores of 

 Lake Canandaigua in 1894, 464. Resemblance of the two species in their life- history, 

 464. Where they are found, 464. Their variation in color and venation, 464. Why 

 they are not more generally collected, 464. They seldom are named in lists, 464. Posi- 

 tion of the Insect when at rest, 464. Are easily captured, 464. How they resent cap- 

 ture, 464. Peculiar carriage of the terminal segments, 465. How the male genital 

 armor is used, 465. Defensive apparatus of European species, 465. A peculiar organ 

 on the fourth abdominal segment of the male, 465. Is probably glandular, emitting 

 an odor attractive to the female, 465. P. maculosa possesses the organ more fully 

 developed, 465. The organ described by McLachlan on a Java species may be homolo- 

 gous with that in our species, 465. Panorpa occasionally seen feeding on a dead fly or 

 larva, 466. It breaks the tissues for liberating the juices, 466. Does not attack living 

 insects unless wounded, 466. Will feed upon the dead of their own species, 466. Also 

 feed greedily upon raw flesh, 466. Kirby and Spence have reported Panorpa as preying 

 on living insects, 466. Seen feeding on fishes, 467. Represented by Prof. Davis as 

 attacking the cotton-worm, 467. The caterpillars may have been injured ones, 467. Its 

 mouth-parts apparently not well adapted for piercing, in contrast to those of Bittacus, 

 467. The economic importance of the question whether it feeds only on dead and 

 wounded insects, 467. Very little solid food taken in the imago stage, 467. Egg-laying 

 habits, 467. Eggs deposited in crevices in sand, 467. The ovaries of the insect, 468. 

 Number of eggs contained in the ovaries, 468. Description of the egg, 468. Duration 

 of egg stage, 463. Description of the young larva, 469. Rapid growth of larva, 469. 

 Changes at moltings, 469 . Ratio of width of hi&d at successive molts tabulated, 470. 



