368 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I37 



semischematic in certain respects such as (i) the stylized treatment 

 of muscle fibers and tracheae, (2) the predominance of black-on- 

 white stippling for the shading of the external surfaces, and (3) of 

 white-on-black stippling for internal skeletal surfaces. The drawings 

 were essentially finished before Niiesch's publications had come to 

 hand ; otherwise some of his conventions might have been adopted in 

 preference to those actually employed. 



The terminology is mainly that of Nuesch and hence is derived 

 from Weber. Nuesch (1953) has identified the muscles of Telea 

 with their presumed homologues in the insects studied by Snodgrass 

 and other writers. It seems possible to homologize virtually all the 

 metathoracic muscles of Crymodes with those figured by Niiesch, 

 and independent comparison with the figures and descriptions given 

 by other authors yields results which are in full agreement with 

 Niiesch's conclusions. 



In the description that follows, the muscles are arranged according 

 to the Weber-Niiesch scheme of classification which is based wholly 

 upon anatomical position and avoids commitments as to action. In 

 many instances the actions may be inferred from the attachments or 

 may be supposed to be as indicated in Snodgrass's classification (1935) 

 which is followed in table i. Direct electrical stimulation of some of 

 the main muscle groups was attempted in a few living noctuids (not 

 in Crymodes) but revealed nothing novel or of special significance. 

 Possible actions of the muscles associated with the tympanum will be 

 considered in the discussion. 



MUSCLES OF THE METATHORAX 

 Dorsolongitudinal muscles 



dlia Plates 5, 12, 16. The separate, fan-shaped fiber bundle of 



the most median of the three muscles described by Eggers 

 (see footnote i). A broad bundle arising on the surface of 

 the prescutum just lateral to the origin of dhb and inserting 

 more or less fanwise on the dorsomedial sclerotization of 

 the tympanic air sac. Note that the prescutum is flexibly 

 hinged by its soft dorsal portion to the anterior margin of 

 the scutum and thus does not afford a rigid attachment for 

 the fibers of this muscle. 



dlib Plates 5, 10, 12, 16. The most median of Eggers's three 



muscles, exclusive of his separate fan-shaped bundle (see 

 dlia. A narrow fan, diverging from the dorsomedial angle 



