Alineuma, Mikhaljova, 2021

Mikhaljova, Elena V., 2021, The millipede family Diplomaragnidae Attems, 1907 in the Asian part of Russia with the descriptions of two new genera and seven new species (Diplopoda, Chordeumatida), Zootaxa 5060 (1), pp. 1-44 : 3

Alineuma gen. nov.

Type and only species: Alineuma rodionovi sp. nov.

Diagnosis. The genus differs from other genera of the family mainly by the thick setose telopodites of the anterior gonopods, which are freely positioned regardless of the colpocoxites, coupled with the mesal sheath processes which transformed into a high trapezoidal structure, which is strongly curved forward.

The new genus seems more closely related to some Japanese Pterygostegia and some Siberian Shearia judged from the large structure formed by the fusion of the mesal sheath processes. In addition, species of Pterygostegia have a small femur of the posterior gonopod telopodites like the one of Alineuma gen. nov. However, the new genus mainly differs from them by the entire anterior angiocoxal processes, distal parts of which are hidden by a colpoxital fold (in contrast, the distal parts of the anterior angiocoxal processes and their branches are not hidden by a colpoxital fold in Shearia , or one of the branches is piercing the colpocoxite in Pterygostegia ).

Description. Body with 32 rings. Eyes present, triangular. Medium-sized paraterga well-developed, horizontal. Leg pairs 3–7somewhat enlarged.Legs 10 and 11 with coxal glands.Telopodites of anterior gonopods subflagelliform, 1-segmented, not sheathed. Posterior gonopods with the mesal sheath processes transformed into a very high trapezoidal structure. Colpocoxites fused mediobasally. Each colpocoxite entire. Posterior gonopod angiocoxites with subglobule in posterior view and depressed in central part. Posterior angiocoxal processes present. Anterior angiocoxal processes very large, broad, their distal parts hidden by a colpoxital fold. Posterior gonopod telopodites 2-segmented, setose, prefemur with a thin stem, femur small.

Etymology. The generic name refers to the second part of the name of the Sikhote-Alin mountain system including Mt. Litovka, where the type species was collected. Gender feminine.

Distribution. Russia: Far East (Primorsky Krai).

Remarks. Shear in his review of Diplomaragnidae (1990) named the positioning of the anterior gonopod telopodites in sheathing grooves on the posterior surfaces of the posterior gonopod colpocoxites one of the main characters of the family. The shape, size and positioning of the telopodites varies ( Mikhaljova 2000). As a rule, the large telopodites are not sheathed, but they lie in the concave colpocoxites. However, subflagelliform and flagelliform telopodites are positioned inside the sheath grooves, sometimes with elevated and closed edges. In contrast, the free positioning (regardless of the colpocoxites) of the anterior gonopod telopodites in the new genus is unique within the family Diplomaragnidae . This character should be included in the description and diagnosis of the family.