The Atoll of Funafuti, Ellice group : its zoology, botany, ethnology and general structure based on collections made by Charles Hedley of the Australian Museum, Sydney, N.S.W.
A genus of the Cerithiidæ, nearest allied to Cerithiopsis. It shares with that the excavated base, the produced canal, and the unfinished aperture; but differs by greater size, broader shell, page 437more rapidly increasing whorls, different plan of sculpture, and especially by a habit of plugging and breaking off the upper whorls from time to time. Animal unknown.
Type. —C. decollatus, Hedley.
The genus is founded on a species from Funafuti. I have also a cogeneric but apparently distinct species from Oubatche, New Caledonia, which is 15 mm. long; white, with a few scattered brown dots; without the longitudinal plications of the Funafuti species, but rather more distinctly cancellated by longitudinal sculpture. I am also disposed to include under Contumax the species which Melvill and Standen describe* as Mathilda eurytima, whose "canali producto" so ill agrees with Mathilda. Perhaps this M. eurytima may be the young of the Oubatche shell just mentioned. The genus is also represented from Torres Straits.
* Melvill & Standen—Journ. Conch, viii., 1896, p. 310, pl. xi., fig. 73.