Reports of Geological Explorations, 1870–71, p. 10, as Conchothyra parasitica, McCoy. But, as no description of it has yet appeared—further than in a footnote by myself in the Reports of Geological Explorations, 1873–74, p. 35—I presume that it is a manuscript name sent by Sir F. McCoy to Sir J. von Haast. This omission I propose now to supply, with the help of some figures drawn for me by Miss Gordon Rich.

Genus Conchothyra.

Shell in the young fusiform, the spire acute and about one-third the length of the whole shell. The columella nearly straight. In the adult the shell is globose; the inner lip with a strong callosity which extends over the anterior end of the aperture, and, in old individuals, covers the whole shell. Columella curved to the right. Aperture rather narrow; the outer lip developed into a massive lobe, slightly notched above and below.

Perhaps identical with Pugnellus, Conrad, but differs in the adult in the columella being curved, and the anterior canal not being produced. Also, the incrustation is much thicker.

C. parasitica. Pl. XLIII., figs. 1–5.

Spire acute, of four whorls, shorter than the body whorl, apparently smooth. Incrustation smooth on the aperture, but rough with growth-lines on the exterior. Lobe of outer lip with nearly parallel sides, rounded at the end, and reaching nearly to the anterior end of the shell. Length, 47mm.; breadth, 50mm. Aperture—length 26mm., breadth 14mm.

Explanation of Plate XLIII.

Conchothyra parasitica.

• Fig. 1. Adult shell, natural size, ventral aspect.

• Fig. 2. " " dorsal aspect.

• Fig. 3. " " basal aspect.

• Fig. 4. " " partly decorticated.

• Fig. 5. Young shell (cast), natural size, ventral aspect.