CRYPTOCEPHALUS IN AAIERICA NORTH OF MEXICO 5 



stoutest and among the longest; the second is the shortest. The apical 

 five or six segments are triangular and elongate and longer and 

 broader than the intermediate segments; each apical segment'ls often 

 about the length of the basal segment. The terminal segments are 

 generally darker in color and more pubescent than the others. 



Pronotum: The surface of the pronotum nearly always bears two 

 sizes of punctures. The smaller punctures are often detectable only 

 under higher powers of a microscope and may be absent or obscured 

 by the alutaceous surface of the pronotum. The larger punctures vary- 

 widely in both size and density: they may be just distinguishable from 

 the small punctures or large and coarse. The pronotum is most often 

 nearly evenly rounded throughout and resembles a segment of a 

 sphere. In two species (gibbicollis and aulicus), it is distinctly bulging 

 medially. This shape is present to a lesser extent in other species. In a 

 few species, the pronotum is not evenly rounded but is much flatter in 

 profile than usual, for example, leucomelas Suffrian. The lateral margin 

 is sharp and distinctly raised and meets the anterior margin at nearly 

 a right angle to form a sharp, posteriorly directed point at its hind 

 angle. The pronotum posteriorly is not margined and is closely applied 

 to the elytra. The posterior edge of the pronotum bears numerous fine 

 teeth that are normally concealed when the elytra and pronotum are 

 close together, but usually the first few at each side are visible. 



Scutellum: The scutellum is tongue-shaped and bears a distinct 

 notch at the base. It does not lie flat, is nearly always higher apically, 

 and extends above the surrounding elytra. 



Elytra: The chief surface features of the elytra are the punctures. 

 These nearly always form distinct rows and vary greatly in both size 

 and density. In aU species, the punctures form a scutellar and a mar- 

 ginal row of punctures (fig. 1). Also, in nearly aU species, the remaining 

 punctures form seven, eight, or nine rows (striae). Most often two or 

 three rows at the side are crowded, confused, intertwined, or inter- 

 rupted, and infrequently aU the rows are distinct and even tlu-oughout. 

 In a few cases, the lateral rows are distinct and even but have an 

 additional short series of punctures behind the humerus. The rows are 

 nearly always faintly to distinctly finer apicaUy, and the combined 

 first and second numbered rows and the last numbered row are 

 usuaUy distinct and clearly united at the apex (fig. 2). In some species, 

 the punctures at the apex are confused, and the combined fii-st and 

 second rows and the last row are totally obscured in this area (fig. 3) . 

 When there are nine rows (this, I beheve, is a primitive condition), 

 the following unite at the apex: the second and ninth, the thud and 

 fourth, the fifth and sixth, and the seventh and eighth. The elytral 

 punctures are largest and sparsest in cribripennis Leconte; in most 

 species, the punctures are distinctly smaUer and denser. A sinuous 



