Syngenodrilinae, Chagné & Giani, 1998

Jamieson, Barrie G. M. & Fragoso, Carlos, 2024, A monograph of the Oligochaete family Alluroididae, Zootaxa 5529 (3), pp. 401-435 : 433

Syngenodrilinae gen sp. Chagné & Giani (1998)

Syngenodrilinae gen sp. Chagné & Giani 1998, 134, 21–32.

Four pairs of single pointed sigmoid setae, the dorsal setae in a very lateral position, close to the ventral setae. Setae present on the genital segments and no differentiation of genital setae. Clitellum with a single layer of cells, in segments XIII to XIX (XX?). Female pore just anterior to the setae of XIV.

Pharynx long, well–developed in IV and V. Septal glands 4 pairs, in V, VI, VII and VIII. Septa from 4/5 strongly developed and bulging posteriad (excepting 10/11), Testes in X and XI, with corresponding sperm funnels. Male genital tract not determinable. Ovaries one pair, in XIII; female funnel well–developed on septum 13/14. One pair of lateral spermatheca in IX. A second individual with the genitalia shifted 2 segments anteriorly (testes in VIII and IX, female pores in XII).

Remarks. The lateral position of the dorsal setae and the presence of two pairs of testes (in X and XI) led Chagné & Giani to place the specimens in the subfamily Syngenodrilinae which included the single monospecific genus ( Syngenodrilus ) but they regarded it as a new, unnamed genus. They stated that of 82 specimens only two were mature but that their state of conservation did not permit identification. As they did not report on prostate structures the identification as Syngenodrilinae must remain uncertain. The holandric condition is also seen in Lacandodrilus but is a symplesiomorpy widespread in oligochaetes and may not indicate close relationship (for further discussion, see previous remarks).