Massylaea massylaea (Morelet, 1851)

Bouaziz-Yahiatene, Houria, Pfarrer, Beat, Medjdoub-Bensaad, Ferroudja & Eike Neubert,, 2017, Revision of Massylaea Moellendorff, 1898 (Stylommatophora, Helicidae), ZooKeys 694, pp. 109-133 : 113-115

Massylaea massylaea (Morelet, 1851) Figs 3, 4-8

Helix massylaea Morelet, 1851; Journal de Conchyliologie 2: 354, pl. 9, fig. 1, 2 [La province de Constantine].

Helix punica Morelet, 1851; Journal de Conchyliologie 2: 352, pl. 9, fig. 3, 4 [habite la grande plaine de Temlouk, au sud-est de Constantine].

Helix massylaea var. concolor Bourguignat, 1863; Malacologie de l’Algérie I: 109, plate 9 fig. 9 [no type locality given].

Helix massylaea var. conoïdea Bourguignat, 1863; Malacologie de l’Algérie I: 109 [Ouled-Sultan (Deshayes)].

Helix nitefacta Bourguignat in Péchaud 1883; Excursions malagologiques dans le nord de l’Afrique de La Calle a Alger, d’Alger a Tanger: 99 [ l’Aurès oriental à Aïn-Tamagra, au sud de Khenchala].

Helix massylaea var. zenatia Kobelt, 1887; Iconographie, (2) 3(1): 3 [Wed Zenati].

Helix punica var. speculatorum Kobelt, 1887; Iconographie, (2) 3(1): 6, Taf. 63, fig. 320-322 [El Kantara].

Massylaea (?) severinae Pallary, 1918; Bulletin de la Société d’histoire naturelle d’Afrique du Nord 9(7): 148 [ Aïn el Bey (Constantine) (Philippe Thomas)].

Type specimens.

massylaea : 2 syntypes NHMUK 1893.2.4.43.5-6; concolor : syntypes MHNG-MOLL 118330/3 (Constantine on label in coll.); conoidea : not found in coll. Bourguignat; nitefacta : syntype MHNG-MOLL 118331/1; zenatia : not researched; speculatorum : not researched; punica : 3 syntypes NHMUK 1893.2.4.1240-1242; severinae: no type specimens found so far.

Other records.

Sigus, 36.1202°N 6.7849°E (Hesse 1920: 41); Tebessa, 35.4142°N 8.1010°E (Hesse 1920: 43, sub punica ).

Diagnosis.

large grey-yellowish shells with maximum four brown spiral bands, aperture whitish to reddish brown, strong surface sculpture of longitudinal grooves.

Description.

Shell large, spire depressed to slightly broad conical, basic colour cream grey-yellowish with brown spiral bands; protoconch large (diameter ca. 5 mm), white; teleoconch whorls regularly increasing, with the last whorl considerably expanding before the aperture, rapidly declining at the aperture; suture deep, surface of teleoconch rough, covered by longitudinal, spirally arranged grooves, sometimes intersected by growth riblets and thus producing a pattern of longitudinal rectangles; spiral bands may be fully developed with maximum four spirals, but all variations including complete fusion of spirals may occur; aperture whitish to reddish brown with a thick lip, columellar part of aperture seldom with a ridge; peristome slightly thickened, umbilicus completely covered by a large reflection of the columellar part of aperture.

Genital organs (only the single subadult specimen (NMBE 519961, sequenced specimen) could be investigated, Fig. 3): Penis short, bulbiform; epiphallus reaching twice the length of penis, with the penis retractor muscle inserting in the distal third of epiphallus; tubiform flagellum reaching the length of penis + epiphallus; penial lumen filled with longitudinal fleshy pilasters; penial chamber with a solid penial papilla (pp2, see also Neubert and Bank 2006); epiphallus opening into the penial chamber via a small pore opposite the "false papilla".

Female part almost undeveloped, the glandulae mucosae only represented by a few small tubules; all other female structures only weakly developed.

Measurements: Syntype massylaea : H = 28.4 mm; D = 40.1 mm; PH = 12.6 mm; PD = 20.5 mm; W = 4.75.

Distribution.

Kobelt (1887) supplied data on the distribution of both, massylaea and punica , and stated that they may occur in hundreds of specimens in a single locality. Given the fact that we here consider punica a synonym of massylaea , this taxon turns out to be one of the most widespread helicoid species in the southern part of the Eastalgerian mountain range covering southwestern parts of the province of Constantine, and parts of the provinces of Biskra and Blida westwards to Schott el Hodna.

Remarks: The variation in shell morphology mainly concerns the elevation of the spire, which may be rather flat to considerably raised. The second character state that varies is the formation, number and colour of the spiral bands. These may be reddish- to chestnut-brown, some may miss completely or in parts, or are fused to form a cloudy brownish surface. Although Kobelt (1887: 3) states that his specimens usually had spiral bands he separated one form without spiral bands under the name zenati, claiming that this form only occurs at this single locality, from which already Bourguignat named his var. concolor . According to the specimens known today, spiral banding is quite stable, but there are all variations seen from five bands to completely unicoloured shells.

Hesse (1920: 43, sub punica ) reports that he received three specimens of this species from Tunisia "Redyef im südlichen Tunis [= Al Rudayyif, Gafsa]. This record has not been reconfirmed by modern collections and is probably based on a confusion with vermiculata .