Ariostralis nebulosa Sirgel, 1985

Sirgel, W. F., 2012, A new species of Oopeltidae (Mollusca, Pulmonata, Arionoidea), with a revision of the subfamily Ariopeltinae and remarks on its affinities within the family and superfamily, African Invertebrates 53 (2), pp. 527-527 : 530

Ariostralis nebulosa Sirgel, 1985

Figs 1 , 2

Ariostralis nebulosa: Sirgel 1985: 481 , figs 7–10.

Emended description (the following is hereby added to the original description):

Proximal part of vagina enlarged to form globular vaginal bulb joined by spermathecal duct ( Fig. 1 ). Second perforated wall, isolated from outer one but suspended from it by thin strands, present in vaginal bulb ( Fig. 2 ). This internal structure consists of cartilaginous material covered by epithelium. Distally, vaginal bulb followed by longer, more slender, but still relatively thick tubular part of vagina. Penis consists of four successive regions, first (proximal) section being a short, slender duct proximally joined by vas deferens next to insertion of penis retractor. This region passes into equally short but slightly wider second part having small subepidermal spines intruding into lumen. These two regions describe an arch and are separated from extensively dilated and longer section by sphincter muscle. Internally, this third region carries much larger subepidermal calcareous spines. Close to its proximal end, wall evaginated towards proximal end of penis. The pocket thus formed carries an almost triangular, subepidermal spine that is many times larger than others. Its apex extends into main lumen of penis. Some of fibres of penis retractor muscle extend past its insertion on to first region to insert on to pocket carrying giant spine. Third region of penis gradually tapers distally to pass into fourth region, consisting of relatively slender duct of varying length and devoid of spinous structures in its lumen. Distally, fourth region passes into the extremely small genital atrium, extending through body wall to open via genital aperture.

Figures

Fig.1. Ariostralis nebulosa, genital system.Abbreviations:ALB GL – albumen gland, GA – genital aperture, G ATR – genital atrium, OV – free oviduct, OVOT – ovotestis, PR – penis retractor muscle, SPOV– spermoviduct, SPT – spermatheca, Vag – vagina, VAG B – vaginal bulb, Vd – vas deferens, 1–4 indicate the successive parts of the penis. (From Sirgel 1985)

Fig. 2. Ariostralis nebulosa, inner perforated wall of the vaginal bulb removed and photographed from its outer side.Abbreviations: PRF – perforations, SP STR – tissue strands suspending the inner wall of the vaginal bulb from its outer wall.