THE MOLLUSCA HEDLEY. 



437 



more 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. 



CONTUMAX DECOLLATUS, sp. nov. 

 (Fig. 25). 



Shell narrow, conical, above rounded, 

 below turreted, solid, in variably decollated. 

 Colour, dull white. Whorls of an uncer- 

 tain number, the specimen figured has 

 seven, and I estimate that five more have 

 been lost. Sculpture the shell has three 

 stages, which merge into each other, but 

 which apart might seem to belong to 

 different species. None of a fairly large 

 series before me show the apical whorls, 

 the summit being in every instance and in 

 successive stages broken off. The youngest 

 whorl before me is rounded and crossed by 

 several fine raised spiral lines. Later the 

 median line enlarges and originates an 

 angle, and a faint longitudinal sculpture 

 appears. Further on, the whorl is sharply 

 angled by a strong keel, below which are 

 two minor keels, and on the shelf above 

 are five delicate spiral lines, all of which 

 are more or less beaded by transverse 

 sculpture. On the antepenultimate whorl 

 commence longitudinal plications which 

 rapidly develop to their maximum on the last whorl. Here they 

 are six in number, oblique, commencing at the suture, most 

 prominent on the shoulder and vanishing at the basal keel. 



The base is hollow, overhung by a thick basal ridge, within 

 which is a second lesser one, the remainder of the base being 

 faintly concentrically striated. Aperture scarcely oblique, squarish, 



Fig. 25. 



* Melvill & Standen Journ. Conch, viii., 1896, p. 310, pi. xi., fig. 73. 



