INTRODUCTION 33 



includes the following : Pachyncmatus affinis Marlatt, Pachy- 

 ncmatus gotarus sp. nov., Euura insularis sp. nov., Pontania 

 5 spp. nov., Pteronus shumagcnsis sp. nov., Dolerus elderi sp. 

 nov., Pachyprotasis nigrofasciatus Esch., Tenthredo ferrugine- 

 tpes Cr., T. vartptcta Nort., T. mellina Nort., T. harrimani 

 sp. nov., T. dissimulans sp. nov., T. bivittata sp. nov., Trichio- 

 soma trianguhim Kby., ard Allantus heraclei sp. nov. The 

 species of Tenthredo were of special interest. At all previous 

 stations the members of this genus had been of species known 

 to be of widespread distribution on the Pacific Coast and else- 

 where. At Popof Island all but three of these familiar forms 

 were lacking and their places were occupied by species hitherto 

 unknown to science. Of the new forms the most striking was 

 Tenthredo dissimulans, which is of a peculiar greenish color, and 

 makes its home upon the umbels of Heracleum. Here it lies in 

 wait for unwary visitors, especially Diptera, and being colored 

 in harmony with the greenish flower stalks among which it 

 lives, gives no warning to its victims. All of the Tenthredos 

 were found on the flowers of Heracleum, and the same was true 

 of Allantus heraclei. 



Of parasitic Hymenoptera Mr. Ashmead has determined 55 

 species from Popof Island, of which only five had been pre- 

 viously described. One genus (Hypocryptus) was new to the 

 American fauna, and the same is true of the species Ischneutes 

 reunitor Nees, a European type of the Braconidas. 



The Heteroptera of the island included two Capsids and three 

 species of Corisa. The Homoptera were better represented by 

 nine species, of which five were leaf-hoppers ; one {Nectar- 

 ophora epilobii sp. nov.) belonged to the Aphidae and two to 

 the Psyllidae. 



The series of Neuropteroids was unexpectedly large, com- 

 prising fourteen species. The list includes two members of the 

 Perlidae, three Ephemeridae, and nine Trichoptera. Several 

 large dragon-flies were observed, but they escaped capture. 

 They were evidently of the same species (/Eschna juncea L.) as 

 an individual captured on the neighboring island of Unga by 

 Professor Ritter. 



The arachnid fauna was not very extensive, including but 



