Helicarionidae Bourguignat, 1877

Muratov, Igor V., 2010, Terrestrial molluscs of Cabo Delgado and adjacent inland areas of north-eastern Mozambique, African Invertebrates 51 (2), pp. 255-255 : 278-279

Family Helicarionidae Bourguignat, 1877

Medium to large snails with a well developed shell, as well as various semi-slugs and slugs. Live in tropical and subtropical areas except Australia and America.

“ Sitala ” jenynsi ( Pfeiffer, 1845)

Figs 48 , 62

Helix jenynsi: Pfeiffer 1845: 131 (Collection of H. Cuming; 7.5×12.0 mm).

A common East African species, with a general distribution from Kenya to central Mozambique. Found at seven stations inland and at all three stations on Cabo Delgado. Pfeiffer (1845) described the shell as “… turbiniformi, … carinata, …” from unknown locality and unfortunately did not give any illustrations. Reeve (1853: pl. 150, fig. 979) reported this species from New Caledonia and illustrated a shell with a more angulated periphery but still not as carinated as illustrated here. Von Martens (1867: 254) then reported it from Java and New Hebrides, as well as from the Querimba Islands (just south of Cabo Delgado). All shells from Cabo Delgado have an obtusely angulated periphery, similar to that illustrated by Philippi (1847: 86; Helix pl. 7, fig. 8). Philippi’s figures were copied by Pfeiffer (1852: pl. 129, figs 23, 24; 1853: 321) and Tryon (1886: 50; pl. 24, figs 87, 88).

A live-collected subadult from station 10 has essentially the same genitalia as illustrated by Verdcourt (1963: 191, fig. 1), who treated jenynsi as Sitala following Thiele (1931). This species does not have any penial appendages besides a small flagellum, which prevents its formal placement into Trochonanina . However, the penial retractor is connected at the base of flagellum and the vagina is long – characters that prevent its formal placement in Sitala . The shell is clearly much more similar to Trochonanina than to Sitala . I suspect that jenynsi in fact should have remained in Trochonanina (perhaps as a separate subgenus). However, I do not have any choice but to treat it as “ Sitala ” since this paper is not a taxonomic revision.

It differs from three following species by the slightly larger shell with microscopic spiral sculpture on the entire surface and a chestnut line above the periphery as well as above the suture of the apical whorls. The shells from Cabo Delgado have a shape quite similar to that of the following species.

Figures

Figs 46–52. Euconulidae:(46) Microcystina minima, 0.68×1.20 mm, stn 7; (47) Afroguppya rumrutiensis, 1.3×1.9 mm,stn 7; Helicarionidae:(48)“Sitala” jenynsi, 10.5×16.0 mm,stn 12; (49) Trochonanina albopicta, 7.5×11.5 mm,stn 5; (50) T.bloyeti, 5.8×12.0mm,stn 17; (51) Trochozonites crenulata, 9.3×12.0 mm, subadult, stn 7; (52) Quickia concisa, 6.0×3.9 mm, stn 7. Scale bar 1 mm in Figs 46–47; 5 mm in Figs 48–52.

Figs 62–65. Helicarionidae: (62) “Sitala” jenynsi, shell 7.9×11.0 mm, subadult, stn 8. Urocyclidae: (63) Bukobia uhehensis, length 35 mm, stn 1; (64) Elisolimax flavescens, length 40 mm, stn 8; (65) Urocyclus kirki, length 75 mm, stn 10.