12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. IO3 



V. STAPHYLINOIDEA 



The adults studied in this superfamily are Silpha americana L., 

 Silphidae (figs. 29, 30, 31), and Creophilus villosus Grav., Staphy- 

 linidae. In Silpha the labral muscles are present. The compressor 

 muscle of the labrum, i, is well developed (fig. 31), and the ventral 

 muscle of the labrum, j (fig. 31), is inserted on the labrum by means 

 of a long, thin tendon. The dorsal dilator muscles of the cibarium, 

 5, 6, and 7 (figs. 29, 31 ) , the compressor muscle group of the cibarium, 

 12 (figs. 29, 31), the dorsal dilator muscles of the pJmrynx, p and 



11 (figs. 29, 31), and the muscle of hypopharyngeal bar Y, 10 (figs. 

 29, 31), are all massive and undoubtedly furnish the power for a 

 strong and efficient sucking mechanism. The musculature of the 

 labium is essentially the same as that found in Periplaneta, excepting 

 the salivary muscles, which are not found in Coleoptera. The muscle 

 of the hypopharynx, ip (figs. 30, 31), the dorsal and ventral muscles 

 of the labium, 20 and 21 (figs. 30, 31), the muscle of the prementum, 

 22 (figs. 30, 31), and the levator m/uscle of the labial palpus, 2/\. (fig. 

 30), are present. The preoral cavity is provided with a sizeable, nar- 

 row lobe (fig. 31) that extends downward from the cibarial wall and 

 also is equipped with a suboral grooved shelf (fig. 31) that originates 

 in the posterior dorsal region of the labium, and which receives the 

 cibarial lobe in somewhat of a semi-piston-and-cyHnder relationship, 

 possibly to facilitate sucking operations. 



In Creophilus the labial muscles are the same in number and ar- 

 rangement as in Silpha; they arise slightly more posteriorly on the 

 gular sutures. The labral muscles are similar also except that the 

 ventral muscle of the labrum, 5, arises on the anterior surface of the 

 distal end of the anterior tentorial arm at the junction of the arm 

 and the head wall. The muscles of the cibarial and pharyngeal regions 

 are practically the same as those found in Silpha. 



Silpha americana L., Silphidae (figs. 32, 33, 34), and a specimen 

 of Staphylinae of the Staphylinidae are the two larval forms used 

 for study. The muscles in Silpha are very well developed. The com^- 

 pressor muscle of the labrum, i, is absent and the ventral muscle of 

 the labrum, 5 (figs. 32, 34), is strong. The dorsal dilator muscles 

 of the cibarium, 5, 6, and 7 (figs. 32, 34), have become grouped to- 

 gether in a large mass. The cmnpressor muscle group of the cibarium, 



12 (figs. 32, 34), is well developed as are the dorsal dilator muscles 

 of the pharynx, p and 11 (figs. 32, 34). The muscle of hypo- 

 pharyngeal bar Y, 10 (fig. 34), is strong and multibranched. Muscle 

 II A (fig. 34), is an additional dorsal dilator of the pharynx which 

 possibly belongs to the dorsal dilator muscle group of the pharynx. 



