56 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



form type differs, however, from that of the Scolytidae with which 

 Doctor Hopkins dealt, and his terminology elaborated for the 

 Scolytidse is therefore not immediately applicable to the campodei- 

 forni larvae. In the hope of finding a foundation for a natural 

 and logical terminology for the body of this type, I began, some 

 years ago, a detailed study both of the external and internal sur- 

 faces of the skin as well as of the arrangement of the muscles in 

 these larvae. I have been fortunate in being able to continue 

 these studies under most favorable conditions since my arrival 

 in this country. In Denmark, I studied more particularly the 

 Carabid, Dytiscid and Hydrophilid larvae, while here the Tro- 

 gositid, Clerid and Elaterid larvae were chosen, because they play 

 a more important role in the Branch of Forest Insects, with which 

 I became connected. 



Some of the results of these studies are presented in this paper, 

 and I believe they will be found useful in the study of other cam- 

 podeiform larvae. The eventual application of these results also 

 to the deviating eruciform type to which the Scolytidae belong, I 

 purposely postpone. I believe that the characters of these two 

 groups eventually may be homologized, but this will involve 

 considerable further anatomical study and the question is not 

 taken up in this paper. From the insufficient investigations I 

 have made of Lepidopterous, Hymenopterous and Neiiropterous 

 larvae, I am inclined to believe that the characters described in 

 the present paper will be found useful in the larval study of all 

 the insects with complete metamorphosis. 



While the terminology has been derived from an anatomical 

 study of the inside of the integuments and of the muscles, the 

 structures can also be made out externally, but they can only be 

 understood by a study of the inside, and it would have been im- 

 possible to homologize the external characters without a com- 

 parative study of the muscles. It should be stated however 

 that the terms used in this paper for the various structural parts 

 are purely provisional. The limitation and definition of the 

 areas has been the main object; the names have been a minor 

 consideration. 



THE INTERSEGMENTAL SKIN 



The segments of an insect larva are, as is well known, connected 

 by a perpendicular inter segmental skin, but a more intimate study 

 of this skin has never been made. This intersegmental skin is 

 divided on each side into two more or less wedge-shaped parts: 

 the superior cunea (s) with the point downwards, and the inferior 

 cunea (i) with the point upwards. The ends of these two cuneae 

 pass each other more or less, that of the superior cunea always 



