Oxychilus cellarius

Oxychilus cellarius (O. F. Müller, 1774) Fig. 6 Worldwide distribution. Originally described from a wine cellar in Copenhagen (Müller 1774). Its native range includes northern and western Europe (Horáčková and Juřičková 2009), Asia Minor, and North Africa (Roth and Sadeghian 2003). It has been introduced into Tasmania (Kershaw 1991), Greenland, North America (Forsyth 2004), St Helena, South Africa, Chile (Stuardo and Vega 1985), Hawaii (Cowie 1997), Australia and New Zealand (Barker 1999). Distribution in Mexico. CDMX (Tlalpan). Diagnostic features. Two specimens were dissected. The penis is cylindrical with a relatively constant width in the middle portion (Fig. 6 D, G). Internally the proximal penis shows small, evenly distributed papillae that tend to be joined together in rows which occasionally form undulating folds (Fig. 6 F, I). The distal penis presents four, thin, internal folds (Fig. 6 E, H). Shell discoidal, flattened, convex (Fig. 6 C), light yellowish in color with fine lines of radial growth (Fig. 6 A). Shell whorls: 4 ½ – 5. Umbilicus slightly flared, ~ 1 / 12 of maximum shell diameter (Fig. 6 B). Shell dimensions: 8–10 mm diameter, 4 mm height (Fig. 7). Aperture width 3–4 mm. Radula (n = 2) composed of 35 rows with ~ 25 teeth / row (Fig. 8 C). Radular formula: C / 3 + 2–3 L / 3 + 0–1 LM / 2 + 9–14 M / 1.