Dadagulella delta Rowson & Tattersfield 2013, sp. nov.
Creators: name: Rowson, Ben
name: Tattersfield, Peter
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Stylommatophora
Streptaxidae
Dadagulella
Dadagulella delta

description: Dadagulella delta sp. nov.
urn:lsid:zoobank.org:act: BF3B 1698 -C8EF-4B28-89A8-D1AA85773A42
Figs 35, 72, 76, 81, 84; Table 1
“ Gulella sp. 12” – Tattersfield et al. 2006: 52-53.
Etymology
From Greek ‘ delta ’, after the letter we originally used as an informal morphospecies name for the species; used as a noun in apposition.
Type material examined
TANZANIA: holotype NMW.Z.2003.001.00019: 1 ad., Mt. Mwanihana Forest Reserve (7.82°S, 36.83°E), Udzungwa Mts National Park, Kilombero District, forest at 1050 m alt., leg. BR, PT, MBS & CFN, 29 Jan. 2003. Paratype NMW. Z. 2003.001.00020: 1 ad., data as holotype but 1200 m alt., 30 Jan. 2003.
Other material examined
None.
Description
SHELL (Fig 32). Large (4.20 - 4.30 mm high x 2.10 - 2.40 mm wide), of 6.5 whorls. Ovate-acuminate, spire broadly acuminate (spire angle 56 - 66°). Apex pointed. Embryonic whorls smoothly granulate. Later whorls with coarse, sinuous ribs (12-13 per mm on penultimate whorl). Sutures of intermediate depth. Umbilicus narrowly open. Peristome incomplete parietally. Outer palatal surface of aperture with a depression corresponding to the palatal tooth. Dentition weak, 3-fold (although could be interpreted as 2-fold or 4-fold), consisting of: one lamella-like parietal tooth; one weak palatal tooth, not forming a parieto-palatal sinus; a columellar baffle so deeply set as to be almost invisible in apertural view; and a very weak shallow columellar swelling. Juvenile shells unknown.
CEPHALOPODIUM. Pale cream, with pale tentacle retractors.
SALIVARY GLANDS (Fig. 72). United, soft, not tumid, elongate, bilobed; each duct leaving at the whitened apex of the lobe and evenly thick throughout.
RADULA. Not successfully prepared.
GENITALIA (Figs 76, 81). Vas deferens appearing thickened prior to insertion on penis but actually with an elongate, parallel diverticulum. Penial sheath absent. Interior of penis with weak radial pilasters and small rhombic pads. Apical part of penis with a single large hook, associated with a spatulate “scoop” with microscopically serrated tip. Elsewhere in penis, an elongate cluster of short, simple hooks mounted on rhombic pads.
Range and habitat
Montane forest (1000 - 1200 m) in the Udzungwa Mountains, central Tanzania.
Remarks
This species is distinctive in its simple and weak dentition, weaker than in any other Dadagulella gen. nov. species except in D. rondoensis (Verdcourt, 1994) comb. nov. and D. conoidea (Verdcourt, 1996) comb. nov. which have a more conical shape. It can be distinguished from Gulella udzungwensis
van Bruggen, 2003, which also occurs on Mt. Mwanihana (van Bruggen 2003), by having a more acuminate spire and more pointed apex, deeper sutures, sinuous ribs and no basal tooth.
description: Published as part of 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, pp. 1-46 in European Journal of Taxonomy 37 (37) on pages 24-25, DOI: 10.5852/ejt.2013.37, http://zenodo.org/record/3806770