Xystosomus bisulcifrons, 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 : 27-28

23. Xystosomus bisulcifrons , new species

FIGURES 48 , 50 , 71

TYPE-LOCALITY.— Parahyba River , Brazil.

TYPE-SPECIMEN.—The unique holotype male is in MHNP. It was collected by P. Germain in 1884 on " Rive gauche du Parahyba ."

DESCRIPTION.—Form: Broad and moderately convex with small head and more or less inflated elytra. Easily distinguished from the other species of this group (see below) by the punctate elytra.

Color: Head and body rufopiceous; pronotum and elytra slightly iridescent; appendages testaceous; femora slightly infuscated.

Head: Broad between eyes; frontal furrows moderately impressed, posteriorly convergent and sulcate; eyes medium-sized and slightly prominent.

Pronotum ( Figure 48 ): Broadly transverse (W/ L, x 1.66); otherwise as in X. parainsularis .

Elytra: Each elytron with six rows of serial punctulae, each striate in part; punctulae shallowly im-

pressed and separated by twice or more their own diameter; elytral-stria 8 present in apical third, deeply engraved, sulcate, nonpunctate; chaetotaxy as in X. inflatus except Eo5 and E06 with a sulcus

between them; plica long, evident externally.

Microsculpture: As in X. inflatus , except slightly coarser.

Secondary sexual characters: Male genitalia ( Figure 50 ) characteristic of the species group. Female unknown.

Size: Holotype: length, 3.4 mm; width, 1.6 mm.

NATURAL HISTORY.— Unknown, except the type was collected in September on the bank of a river.

LOCALITY RECORDS ( Figure 71 ).—I have seen only the unique type from Parahyba River, Brazil.

Figures

FIGURE 71 Approximate ranges of the parainsularius group (crosshatched areas).

FIGURES 47, 48.—Pronotum, dorsal aspect: 47, Xystosomus parainsularis, male, "Colombia Oriental"; 48, X. bisulcifrons, male, Rio Parahyba, Brazil.

FIGURES 49, 50. Male genitalia, left lateral aspect: 49, Xystosomus parairuularis, Colonia Tovar, Venezuela; 50, X. bisulcifrons, Rio Parahyba, Brazil.