Cormodesmus Chamberlin, 1923

Alvear, Santiago & Romero-Rincon, Juan, 2024, Contribution to the knowledge of the Colombian Batodesmini (Polydesmida: Chelodesmidae) with the description of a new genus and species, and taxonomic insights on the genus Cormodesmus Chamberlin, 1923, Zootaxa 5523 (5), pp. 553-563 : 558-559

Genus Cormodesmus Chamberlin, 1923

Cormodesmus Chamberlin, 1923: 56 . Attems 1938: 69; Hoffman 1969: 280; Jeekel 1971: 255.

Type species: C. hirrutellus Chamberlin, 1923 , by original designation.

Diagnosis. A batodesminine genus belonging to the Biporodesmus group, characterized by having modified metazonites, with large, irregularly shaped tubercles ( Fig. 6A, C, E ). Paranota are elevated above the dorsum, welldeveloped, thick, and beset with large, round tubercles. Ozopores inconspicuous.

The gonopod of Cormodesmus differs from other genera in the Biporodesmus group by the absence of a field of numerous long setae on the dorsal side of the Cx ( Fig. 7 ), contrasting with their presence in Tunochilus Chamberlin, 1950 and Batodesmus Cook, 1896 . The telopodite has a large, expanded PfP covering the acropodite dorsally ( Fig. 7C, D ). t is small and simple ( Fig. 7A, B ), differing from the multi-branched t in Biporodesmus Attems, 1898 or absent in Tunochilus and Curimaguana Hoffman, 2007 . t is directed ventrad vs. anteriad in Plusioporodesmus Silvestri, 1898 and lateroventrad in Igaraparana Hoffman, 1982 .

Cormodesmus differs from Attemsiella by lacking transverse grooves on the tergites and having large, round tubercles instead of small, irregular ones, and from Colombodesmus by the absence of transverse rows of granules on the dorsal surface of the body rings and by having small pointed sternal projections instead of large sternal spines.

Figures

FIGURE 6. Cormodesmus hirrutellus Chamberlin, 1923 (MHNUC-MD-0302). A, C, E. Anterior, middle and posterior parts of body respectively, dorsal views. B, D, F. Anterior, middle and posterior parts of body respectively, ventral views. Scale bar: 2 mm.

FIGURE 7. Cormodesmus hirrutellus Chamberlin, 1923 (MHNUC-MD-0302). A, B. Left gonopod, mesal view. C, D. Lateral view. Abbreviations: ca: cannula, Cx: gonocoxa, Pfe: prefemoral region, PfP: prefemoral process, S: solenomere, t: tibiotarsal branch. Scale bar: 0.5 mm.