10 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 123 



Type-locality: Brownsville, Cameron Co., Tex. 



Distribution: Other than the holotype from Brownsville, Tex., 

 this species is known at present only from San Luis Potosi, Mexico. 

 The material examined included 35 specimens from the following 

 localities in San Luis Potosi: Tamazunchale, Huichihuayan, and 

 Paj al. 



Triplax flavicollis Lacordaire 



Triplax flavicollis Lacordaire, 1842, p. 218. 



Triplax confinis LeConte, 1854, p. 162. 



Triplax championi Gorham, 1888, p. 78. [New synonymy.] 



Triplax hogei Gorham, 1888, p. 78. [New synonymy.] 



Triplax mesomelas Gorham, 1888, p. 79. [New synonymy.] 



Diagnostic description: Color variable; elytra ranging from fer- 

 rugineous to black; the following yellow to testaceous: head, pronotum, 

 pro thorax, and meso thorax; metathoracic coloration variable, some- 

 times metepisterna and metepimera are black, sometimes entire 

 metathorax is black; abdomen testaceous to piceous; antennal 

 coloration variable, club ranging from reddish yellow to piceous, stem 

 grading from reddish yellow to piceous; body moderately nitidous. 

 Body shape somewhat elliptical, anterior and posterior ends about 

 equally parabolically rounded. Postmandibular lobes short, their 

 lateral edges often somewhat rounded and divergent posteriorly; 

 terminal segments of maxillary palpi moderately widened (see Boyle, 

 1956, p. 164, fig. 76), their width approaching 3 times their length, 

 a distinct brush present along entire apex; mentum small; antennal 

 club gradually 4-segmented. Pronotal punctures of moderate size, 

 not deep; cephalic punctures much larger and denser; elytral striae 

 impressed, small punctures present in elytral intervals; elytra distinctly 

 margined basally. 



Variation: The observed size variation of the 108 Neotropical 

 specimens examined is: length 2.60-5.12 mm; width 1.44-2.81 mm. 



Discussion: The three "species" that Gorham listed as distinct have 

 not been found to be so. A "separation" of the specimens by com- 

 parison of the postmandibular lobes (and coloration of the meta- 

 thorax according to Gorham's descriptions) of T. championi, T. hogei, 

 and T. mesomelas showed intergradation and cast doubt on the tena- 

 bility of these three "species." A comparison of the anterior end of the 

 internal sac of the "three forms" showed that they were conspecific. 



Male genitalia: See Boyle (1956, p. 166, fig. 93). 



Type: Not seen. 



Type-locality: North America. 



Distribution: North America east of the 100th meridian from 

 Quebec to Florida and Texas, south into Mexico and Central America 



