Date of this Version
To date, only two references place members of the genus Diplocentrus in Sonora, Mexico. The first was a passing comment by Francke (1975) that D. spitzeri Stahnke occurs in northeastern Sonora. The specimens he examined and used in his systematic studies on that species are the same as the ones reported here for the first time from a specific Sonoran locality. The second reference was by Sissom and Walker (1992) listing a single record of D. gertschi Sissom and Walker from Libertad on the northern coast.
Examination of material from the American Museum of Natural History (AMNH), the California Academy of Sciences (CAS), and the Academy of Natural Sciences (ANS) indicates that, in addition to D. spitzeri and D. gertschi, another distinct species occurs in the Alamos and Navajoa areas in southern Sonora. This species is described as new below. It should be noted that a juvenile specimen from the vicinity of Benjamin Hill was also examined that was unassignable with certainty to any of the above species. This indicates that the genus has a wider distribution in Sonora than demonstrated even by the specimens listed in this report.
Nomenclature and mensuration utilized herein essentially follows that of Stahnke (1970), with the following exceptions: carinal terminology and cheliceral measurements are after Francke (1975,1977) and trichobothrial terminology is after Vachon (1974). Specimens in the senior author's collection are listed in the records sections as "WDS”.
Because D. spitzeri and the new species are both quite similar to D. peloncil1ensis Francke, the latter is included in the tables for comparison; in addition, the hemispermatophore of this species is also drawn. D. peloncillensis was described from only 6 males, 1 female, and 1 juvenile. The data presented here for D. peloncillensis are derived from these and new specimens available since the original description was published (Francke 1975), thereby providing a better understanding of variation in this species.