430 PROCEEDINGS OF THE NATIONAL MUSEUM vol. in 



tured, becoming even coarser laterally on basal four abdominal ster- " 

 nites; entire ventral surface concolorous with dorsum. Male aedeagus 

 (pi. 5, figs. 35, 36) narrow and elongate; apical sclerite well sclerotized, 

 acutely pointed; basal sclerite strongly ciu-ved basally, constricted 

 just behind apical sclerite; penis membranous and indetectable, 

 struts weakly developed. Measurements: length 4.0-4.6 mm.; width 

 1.9-2.4 mm. 



Remarks. — This seemingly rare species is known only from the 

 mountains of southern Arizona. The elongate, comparatively de- 

 pressed form, the relatively large clypeus which extends backward 

 almost to the eyes, the deep reddish-brown color, the gradually 

 deflexed apex of the prosternal process and the conspicuously punc- 

 tured, slightly convex elytral intervals should suffice to distinguish 

 P. inguilinum from other Nearctic species of Platydema. The rel- 

 atively large male genitalia (pi. 5, figs. 35, 36) indicate no close 

 affinities with other forms studied and its relationships within the 

 genus are not clear. Along with P. micans, it apparently represents 

 a wide divergence from the main line of evolution in Platydema. 



While it is poorly represented in collections it is worthy of note that 

 D. J. and J. N. Knull have accumulated 23 specimens (OSU) from 

 the Chiricahua Mountains. These represent more than half of the 

 total specimens available for this study and suggest that the species 

 is probably much more abundant than we realize. The series is the re- 

 sult of two years' (1952, 1953) collecting, but all were taken in the 

 month of July. 



The type series of fom* specimens was collected by H. G. Hubbard 

 near Tucson, Ariz. (December 23) in nests of a wood rat {Neotoma ai- 

 higula). The specimens collected by the Knulls were all taken under 

 bark, and there probably is no direct association between the beetles 

 and the rodents. 



Type.— USNM 4173: Tucson, Ariz., December 23, Hubbard and 

 Schwarz. Three specimens plus one empty pin constitute the type 

 series. All bear type labels but the first example bears Linell's 

 determination label and is to be regarded as the holotype. 



Specimens examined.— From the following localities, 41 : 



United States: Arizona (Baboquivari ]Mts., Chiricahua Mts., Globe, Patagonia, 

 Pinal Mts., Santa Catalina Mts., Tucson). 



Platydema micans Zimmerman 



Plate 5 (Figs. 33, 34) 



Platydema micans Zimmerman. — Horn, 1870, p. 383. — Blatchley, 1910, p. 1264. 



Description. — Short, broadly oval, strongly convex, dark red- 

 dish brown to black, shining. Head with epistomal margin evenly 



