Dadagulella cuspidata ( Verdcourt, 1962 ) Rowson & Tattersfield, 2013

Rowson, Ben & Tattersfield, Peter, 2013, Revision of Dadagulella gen. nov., the “ Gulella radius group ” (Gastropoda: Streptaxidae) of the eastern Afrotropics, including six new species and three new subspecies, European Journal of Taxonomy 37, pp. 1-46 : 20

Dadagulella cuspidata ( Verdcourt, 1962) comb. nov.

Figs 31 , 59 , 84 ; Table 1

Gulella cuspidata Verdcourt, 1962: 3 , 27-28, pl. 3, fig. 2.

“ Gulella sp. nov. ” – Verdcourt 1958: 94, 100, fig. 10.

Gulella cuspidata – van Bruggen 1969: 71. — Verdcourt 1983: 232. — Richardson 1988: 72. — Verdcourt 1996: 136. — Tattersfield 1998 b: 37. — Tattersfield et al. 1998: 135. — van Bruggen 2000: 233. — Verdcourt 2006: 46. — Rowson & Lange 2007: 31. — Muratov 2010: 277.

Type material examined

TANZANIA: holotype MRAC.792352 : 1 ad., Worlds View, Shume , West Usambara Mts (4.70°S, 38.20°E), in rather dry evergreen forest, leg. B. & L. Verdcourt, Dec. 1956.

Other material examined

None.

Description

SHELL ( Figs 31 , 59 ). Large (4.30 - 4.80 mm high x 1.80 x 2.50 mm wide), of 7.75 whorls. Ovate-acuminate, spire coeloconoid (spire angle 58°). Apex sharply pointed. Embryonic whorls appear smooth but with fine regular radial striae. Later whorls with relatively few, coarse ribs (about 8 per mm on penultimate whorl). Sutures of intermediate depth. Umbilicus narrowly open. Peristome incomplete parietally. Outer palatal surface of aperture with a furrow-like depression corresponding to the upper palatal tooth. Dentition 6-fold (alternatively recognisable as 5-fold), consisting of: one lamella-like parietal tooth; two palatal teeth, the upper much larger and forming a parieto-palatal sinus; one basal, in-running tooth; and a strong, squarish columellar tooth, running in to form a columellar baffle which is connected to it. Juvenile shells and anatomy unknown.

Range and habitat

Elevation not stated but probably between 1500-2000 m at the type locality in northeastern Tanzania.

Remarks

This species differs from D. minareta sp. nov. in having two palatal teeth, in having a basal tooth, in the shape of the parietal tooth, and in size.

Figures

Figs 27-35. Adult shells of Dadagulella gen. nov. species. 27. D. delgada (Muratov, 2010) comb. nov., syntype, Cabo Delgado (after Muratov 2010). 28. D. ecclesiola sp. nov., holotype, Kimboza. 29. D. cresswelli sp. nov., holotype, Ngorongoro. 30. D. minareta sp. nov., holotype, Kimboza. 31. D. cuspidata (Verdcourt, 1962) comb. nov., holotype, Shume. 32. D. pembensis sp. nov., holotype, Ngezi. 33. D. nictitans (Rowson & Lange, 2007) comb. nov., holotype, Macha. 34. D. frontierarum sp. nov., holotype, Mtai. 35. D. delta sp. nov., holotype, Mwanihana.

Figs 51-64. Apertures of adult shells of Dadagulella gen. nov. species (not to scale). 51. D. radius calva, lectotype, Taru Desert. 52. D. radius radius, lectotype, Shimba Hills. 53. D. radius radius, Amboni. 54. D. browni mafiensis subsp. nov., holotype, Mlula. 55. D. browni semulikiensis subsp. nov., holotype, Semuliki NP. 56. D. ecclesiola sp. nov., holotype, Kimboza (two views of shell showing basal tooth only visible when shell angled). 57. D. cresswelli sp. nov., holotype, Ngorongoro. 58. D. minareta sp. nov., holotype, Kimboza. 59. D. cuspidata comb. nov., holotype, Shume (note shell angled slightly differently to that in Fig. 31). 60. D. pembensis sp. nov., holotype, Ngezi. 61. D. frontierarum sp. nov., holotype, Mtai. 62. D. minuscula minuscula, lectotype, Nzwani. 63. D. minuscula minuscula, paralectotype, Nzwani. 64. D. minuscula mahorana subsp. nov., holotype, Mayotte.

Fig. 84. Distribution of Dadagulella gen. nov. species, based on published records and material examined here (for additional records of D. meredithae comb. nov. in northern Malawi see van Bruggen 2000). The inset on the left corresponds to the map on the right.