Plectorhagada, IREDALE, 1933

Taylor, James P. A., Johnson, Michael S. & Stankowski, Sean, 2015, Molecular phylogenetics and complementary geographical distributions of species of the Western Australian land snail genera Plectorhagada Iredale, 1933 and Strepsitaurus Solem, 1997 (Gastropoda: Camaenidae), Zoological Journal of the Linnean Society 174 (2), pp. 305-321 : 315-316

PLECTORHAGADA IREDALE, 1933

Plectorhagada Iredale, 1933: 52 ; 1938: 113; 1939: 69– 71; Burch, 1976: 136; Solem, 1997: 1575–1611.

Type species

Helix plectilis Benson, 1853 , by original description.

Diagnosis

Shell medium sized, variable (adult diameter, D = 10.9– 22.0 mm; height, H = 4.9–18.3 mm), between 3 3/4 and 5 7/8 whorls. Spire very low to very high (H / D = 0.45– 0.99). Apical sculpture with dense to scattered, often elongated micropustules, sometimes arranged in radial rows. At least the upper spire with prominent crenulated ridges (except P. teres sp. nov.). Body whorl rounded (except angulated in P. meilgana ). Umbilicus closed or a narrow lateral crack in the most globose species ( P. carcharias , P. plectilis , P. scolythra , and P. teres sp. nov.), narrowly open in Plectorhagada rovina Iredale, 1939 and P. meilgana , widely open in Plectorhagada gascoynensis (Smith, 1894) . Palatal and basal lips narrowly to moderately reflected and expanded, columellar lip usually wider. Parietal wall callus varying from thin to thick and elevated, lip edge always appressed to parietal wall if thickened. Where known, shell colour light brownish or yellowish suffusion, often with a narrow reddish brown spiral supraperipheral band. Lip white. Genitalia with slightly to greatly enlarged albumen gland. Vagina short to very short, free oviduct and shaft of spermatheca twisted around each other, head of spermatheca reaching just above base of prostate–uterus. Epiphallic caecum either absent or a small knob. Vas deferens very slender, entering directly into slightly expanded head of epiphallus. Epiphallus not circling penial retractor muscle, which inserts in an arc at the point where the epiphallus enters the penis through a simple pore. Penis globular to somewhat elongated, without an identifiable sheath.

Distribution

Species of Plectorhagada range from near the southern tip of Shark Bay, north to the northern edge of the Cape Range along the coast, and up to 160 km inland, as far north as Meilga and Glen Florrie Stations, Western Australia.