Mathilda malvinarum (Melvill & Standen, 1907)

Fig. 5D

Cerithiopsis malvinarum Melvill & Standen, 1907: 135, figs. 6, 6a; Strebel, 1908: 49, pl. 1, figs. 10a–c

Mathilda malvinarum — Powell, 1951: 113

Examined material. 10 sh. (MACN-In 40700).

Description. Shell height to 2.8 mm (up to 4 mm according to Melvill & Standen 1907); turritelliform, moderately solid. Protoconch large, of 1 markedly convex whorl; sculptured with 4 low, wide spiral cords. Teleoconch of up to 5.75 whorls, markedly convex in outline; last whorl comprising about 45% of total shell height. Suture impressed. Surface pale brownish, clearer at spiral sculpture; sculptured with 25 to 30 axial ribs per whorl and 4 spiral cords, the 2 adapical being stronger. Base delimited by a strong cord and sculptured with up to 9 additional, narrower cords. Aperture almost rounded, somewhat projected anteriorly, interior brownish with lighter margin; columellar callus narrow, slightly reflected.

Remarks. The original figure by Melvill & Standen (1907) only shows 2 spiral cords per whorl. However, Strebel (1908), who studied the same specimens, figured four spiral cords per whorl, a condition similar to that found in the material here examined.