Xystosomus elaphrinus, Bates Elytral, 1871

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 : 20-21

The elaphrinus group

The members of the elaphrinus group are characterized by the following: huge hemispherical eyes; narrow, almost square pronotum (narrower than head across eyes); nonsulcate prosternal process; and fully developed flight wings. The characteristics of the internal sac of the male genitalia, including the presence of a "brush sclerite," correspond to those in the members of the gruti group. With the exception of the apex of the stylus, the characteristics of the female genitalia also correspond to those in the members of the gruti group. In the elaphrinus group, the apex is blunt, with the lateral spines exceeding it in length.

Presently known to represent this group are three species with a combined distribution ( Figure 70 ) from Costa Rica to Brazil.

Figures

FIGURE 70 Approximate ranges of the elaphrinus group (crosshatched area) and the micro- tretus group (solid areas).