NO. 7 MUSCULATURE OF COLEOPTERA — DORSEY 21 



rather slender and the oesophagus is small considering the size of the 

 insect. 



The larval forms of Scarabaeoidea studied pertain to Popillia 

 japonica Newman and Cotinis nitida (L.), Scarabaeidae. 



In Popillia (figs. 78, 79, 80) the ventral muscle of the labrum, j 

 (figs. 78, 79), is strong; the muscle of hypo pharyngeal bar Y, 10 

 (figs. 78, 79), is massive. All of the cibarial muscles are absent. 

 The dorsal dilator muscle of the anterior region of the pharynx, 9 

 (fig. 78), is so weak as to be almost threadlike. The compressor 

 muscle group of the ciharium, 12 (fig. 78), is poorly developed. 

 There is a large, heavily sclerotized cuspidate sclerite on the posterior 

 dorsal surface of the labium. The dorsal and ventral muscles of the 

 labium, 20 and 21 (figs. 78, 80), and the muscle of the prementum, 

 22 (figs. 78, 80), are well developed. 



In Cotinis the labral and labial muscles are similar to those in 

 Popillia; the muscle of hypo pharyngeal bar Y, 10, is also similar. 

 There is only one pair of weak muscles inserted on the dorsum of 

 the ciharium just anterior to the frontal connective nerves; it is 

 probably one of the dorsal dilator muscles of the cibarium, 5, 6, or 7. 

 A pair of weak dorsal pharyngeal muscles, probably p, is present. 



XIV. CLEROIDEA 



Dermestes caninus Germ., Dermestidae, and Enoclerus spinolae 

 Lee, Cleridae, are the adult forms studied in this superfamily. 



In Dermestes (figs. 81, 82, 83) the labral, cibarial, pharyngeal, and 

 hypopharyngeal muscles are all well developed. The compressor 

 muscle of the labrum, i, and 5 of the dorsal dilator muscles of the 

 cibarium are absent. The muscle of hypopharyngeal bar Y, 10 (figs. 

 81, 82), is branched as in the generalized form. Bar Y is rather 

 heavy and is continuous ventrally with a sclerotized subpharyngeal 

 rod that connects the bar Y of one side with that of the other. In 

 the labium a muscle is present that might be considered either as the 

 muscle of the prementum, 22, or as the ventral muscle of the labium, 

 21 (figs. 81, 83). It arises medially in the anterior region of the 

 submentum and is inserted medially on the base of the prementum. 

 The muscle 20 (figs. 81, 83) may in reality be homologous with the 

 muscle of the hypopharynx, ip; it arises on the inner surface of the 

 posterior end of the anterior tentorial arm and is inserted medially 

 on the dorsal labial wall in the anterior region by means of a tendon. 



In Enoclerus the musculature is similar to that in Dermestes, with 

 a few variations. One additional pair of ventral muscles of the labium 

 is present. 



