Xystosomus anterocostis, Erwin, 1973

Erwin, Terry L., 1973, Studies of the subtribe Tachyina (Coleoptera: Carabidae: Bembidiini), Part I: A revision of the Neotropical genus Xystosomus Schaum, Smithsonian Contributions to Zoology 140, pp. 1-39 : 14

9. Xystosomus anterocostis , new species

FIGURES 14, 31, 69

TYPE-LOCALITY. — Hamburg Farm at Reventazón , Costa Rica.

TYPE-SPECIMENS.—The holotype male, allotype, and one female paratype are in USNM. All were collected by Nevermann.

DESCRIPTION.—Form: As in X. gruti , except elytra slightly more convex. Easily distinguished among the "smooth elytra-convex interval" group of species by the sinuate sides of the pronotum.

Color: Head and body piceous; pronotum and elytra moderately iridescent; appendages testaceous or slightly infuscated.

Head: Broad Letween eyes; frontal furrows deeply impressed, almost sulcate; eyes large and prominent.

Pronotum ( Figure 14): Transverse (W/ L, x 1.63; range, 1.53-1.75; 3 specimens); otherwise as in X. gruti , except side margins sinuate at basal third.

Elytra: Striae 5-8 well impressed and punctulate; intervals convex, at least in basal third; disc with four rows of faintly impressed punctulae, each well separated from the other, intervals flat; side margins broadly explanate; humeral projection well developed, blunt; chaetotaxy as in X. gruti; plica small, evident externally.

Microsculpture: As in X. gruti .

Secondary sexual characters: Male genitalia ( Figure 31) and female genitalia characteristic ol the species group.

Size: Three specimens: length, 3.3-3.6 mm; width, 1.6-1.8 mm.

NATURAL HISTORY.—F. Nevermann collected two specimens on "wilted foliage of Quararibae turbinata, October" ( Bombacaceae ) and one specimen "on dry leaves, September." No teneral specimens seen.

LOCALITY RECORDS ( Figure 69).—I have seen three specimens from the following locality: CENTRAL AMERICA: COSTA RICA: Hamburg Farm at Reventazon (USNM).