Retrodesmus Chamberlin, 1945

Golovatch, Sergei I., Geoffroy, Jean-Jacques, Stoev, Pavel & Spiegel, Didier Vanden, 2013, Review of the millipede family Opisotretidae (Diplopoda, Polydesmida), with descriptions of new species, ZooKeys 302, pp. 13-77 : 28-30

Genus Retrodesmus Chamberlin, 1945

Retrodesmus Chamberlin, 1945: 4.

Retrodesmus - Hoffman 1982: 722; Simonsen 1990: 53.

Diagnosis.

A genus of Opisotretidae with 19 (♂) or 20 (♀) body segments. ♂ vertex without modifications. Metaterga with three regular, transverse rows of bacilliform setae, but, in conjunction with frontolateral margin of midbody paraterga bearing evident shoulders, all three rows strongly shifted caudad, last two being also abbreviated. Ozopore from well removed from, to very near caudal margin of paratergite’s caudolateral incision.

Gonopod telopodite rather stout, only slightly curved, unipartite, divided only distally into a frontal stump heavily beset with bacilliform ornamentions and a simple to complex caudal branch; seminal groove terminating near base of both these branches; neither a solenomere nor a hairy pulvillus (Figs 13B, 15C, D, 16B, C), only sometimes with a visible accessory seminal chamber.

Type species.

Retrodesmus dammermani Chamberlin, 1945, by original designation.

Remarks.

The holotype of this species has been examined in order to shed light on the identity of both the genus and species. A new species is added as well. The differences between both are clear from Figs 12, 13 and Figs 14-16, as well as from the diagnosis of Retrodesmus cavernicola sp. n.