658 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 117 



of the pronotum. The first five segments are narrow while the apical 

 six become wider, more triangular in shape. Antennal segmental 

 coloration varies within species by the number of basal segments, 

 which are of lighter hues. The mouth parts are difficult to observe 

 due to the hypognathous head. The rounded labrum often is lighter, 

 as are the basal antennal segments. The terminal segments of the 

 labial and maxillary palpi are gradually accuminated. The mentum 

 is not visible. 



Pronotal convexity greatly contributes to a compact shape. The 

 rapidity of taper of the pronotum as it narrows anteriorly yields 

 varying degrees of robustness. (Some species have the lateral edges 

 of the pronotum more nearly parallel than others.) Since the pro- 

 notal lateral margins lie beneath the curvature of the body, they 

 are invisible from above. Slightly below the middle these form right 

 angles where they meet the anterior pronotal margin. Pronotal 

 markings are of some specific distinctive value, but punctation and 

 sculpture are also quite variable. Setae can be seen at the four 

 pronotal angles on clean specimens. No diagnostic value was placed 

 on the long and narrowly triangular scutellum. 



Elytral striae become obscure near the posterior end. Interstrial 

 punctures are much finer than the strial. In some species the sub- 

 marginal striae are more deeply impressed than the remainder, and 

 the epipleura are well developed along the thorax but narrow quickly 

 along the abdomen. 



The transversely subrectangular prosternum extends between the 

 two anterior coxal ca\dties, which are closed behind. The middle 

 coxal cavities are open behind. Mesopleural and metapleural sclerites 

 are distinct. The mesosternum is subrectangular, approximately 

 twice as broad as long, and the metasternum is likewise wider than 

 long. Median sutures and sternal coxal lines can also be seen on 

 some species, and various degrees of punctation are noticeable on 

 the thoracic sternites and pleurites. 



The abdomen is composed of five sternites, the first being the 

 widest. This basal sternite has a broad (often % the width), truncate 

 intercoxal process. The length of all five abdominal sternites to- 

 gether does not equal the width of the abdomen. Punctation and 

 rugosities on the abdominal sternites sometimes allow specific dis- 

 tinctions. Sexual differences are visible on the fifth abdominal 

 sternite. 



The legs are always widely separated. The anterior and middle 

 coxae are globular; those of the hindlegs are transverse. The tro- 

 chanters are shaped like right triangles with their "hypotenuses" 

 bounding the femoral base. The femora are slightly swollen — the 

 anterior the most and the hind the least. A shallow groove is notice- 



