NO. 7 MUSCULATURE OF COLEOPTERA — ^DORSEY I9 



examined, but only the ventral muscle of the labrum, j, was found 

 to be present ; muscle j in this species is unusual in that it originates 

 laterally in the anterior clypeal region (fig. 74). This condition has 

 been observed only in this species. 



In Neotrichophorus the cibarial, pharyngeal, and hypopharyngeal 

 muscles are of the usual form (figs. 68, 70). Hypopharyngeal bar 

 Y more or less parallels the lateral margins of the cibarium and is 

 joined to the bar Y on the opposite side by a subpharyngeal support- 

 ing area on which are inserted strong ventral dilator muscles of the 

 pharynx, 50 (fig. 68). The labial and hypopharyngeal muscles are 

 of generalized form, though the ventral muscle of the labium, 21, is 

 absent unless the muscle of the prementum, 22 (figs. 68, 69), has 

 been misinterpreted as 21, in which case, of course, muscle 22 would 

 be absent. 



In Chrysobothris the labial and palpal muscles are similar to those 

 in Neotrichophorus ; the muscle of the prementum, 22, is absent. The 

 labral muscles are also similar except that the dorsal muscle of the 

 labrum, 4, is absent; the ventral muscle of the labrum, 5, arises in 

 the midfrontal region on the inner (mesal) surface of the suture that 

 separates the inner margin of the compound eye from the frons. The 

 cibarial, pharyngeal, and hypopharyngeal muscles are essentially the 

 same, but are all poorly developed. 



Parallelostethus attenuatus (Say) (figs. 71, 72, 73), Alaus sp., 

 Elateridae, and Cebrio antennatus Schfr., Cebrionidae, are the larvae 

 studied in this superfamily. 



In Parallelostethus the labral muscles are absent. The cibarial, 

 pharyngeal, and hypopharyngeal muscles are powerful, but other- 

 wise similar to those found in the adult Neotrichophorus; hypo- 

 pharyngeal bar Y is also similar. The labial muscles, except for being 

 long and thin (figs. 72, 73), are of the generalized form. The extra 

 length is made possible by a posterior, spurlike extension of the 

 anterior tentorial arm (fig. 73) ; the dorsal and ventral muscles of the 

 labium, 20 and 21, arise on the inner surface on the posterior tip 

 of this spurlike extension. 



In Alaus sp. the musculature is essentially the same as that in Paral- 

 lelostethus, and in the cebrionid larva, Cebrio, the muscles were found 

 to be practically the same as those in the two elaterid larvae studied. 



XIII. SCARABAEOIDEA 



The adults of Popillia japonica Newman and Macrodactylus sub- 

 spinosus (Fab.), Scarabaeidae, and Lucanus placidus Say, Lucanidae, 

 were selected for study in this superfamily. 



