Althanus Lewis, 1903: 420 [type species: Althanus teretrioides Lewis, 1903: 420]; Cooman, 1939: 137; 1941: 41; Ohara & Mazur, 2000.
Notes (Ohara & Mazur, 2000).
Althanus Lewis comprises two species: A. teretrioides Lewis, 1903 (Mentawei Is.) and A. annamita Cooman, 1939 (Vietnam). Both these species differ from the rest of the tribe Platysomatini in the cylindrical body, shortened marginal pronotal stria, asymmetrical labrum and the possession of a strong angle at the base of the inner edge of protibia (Fig. 1F, G). Lewis (1903) placed originally this genus near Cylister and Platysoma on the basis of the sternal structure and the antennal fossae. He (1914) also mentioned that the peculiar angulation of protibia was not an important character for systematical placement. Bickhardt (1917) followed the Lewis's treatment. In 1939 and 1940, Cooman, however, transferred the genus Althanus to the subfamily Teretriinae (now treated as a tribe of the subfamily Abraeinae) and erected a new tribe, "Althanini", for the following reasons: 1) Althanus shares the key characteristic of Teretriinae and Abraeinae, the antennal foveola (a small fovea connected with antennal scape), shaped into a deep emargination on the anterior margin in front of eye (Fig. 1A); 2) cylindrical body is only to be found in Teretriinae; 3) tribe Althanini is distinguished from the tribe Teretriini by round posterior margin of the prosternal process, sinuous anterior margin of mesosternum and having prosternal lobe. Thereafter Mazur (1984) transferred again the genus to the tribe Platysomatini (Histerinae) in his catalogue and synonymized the tribe Althanini with it.
Although our observation is based only one female, we do not accept Coomans opinion for the following reasons: 1) emargination of the antennal foveola is not so deep as in Teretriini; 2) labrum has no setae; and 3) structure of antennal cavity (fossettes) on prosternum is different from that of the Teretriini (type 4, not 7: Ohara, 1994: 24-27). Althanus is probably more closely related to Platysoma or Cylister.
Distribution. Southeast Asia (Indonesia: Mentawei Is.; Vietnam).