12 STUDIES ON AUSTRALIAN MOLLUSCA, 



•extremity are four or five grooves and keels diminishing succes- 

 sively. On the spire the double row of l^eads and peripheral keel 

 alone appear. Aperture slightly oblique, ovate, with a heavy 

 callus and single stout deep-seated tooth on the parietal wall; the 

 throat traversed by six ridges. Height 1-72, breadth 088 mm. 



//«6. —Princess Charlotte Bay, N. Queensland, 13 fathoms, 

 sandy mud bottom; three specimens (J. Brazier). 



Type to be presented to the Australian Museum. 



Crosse A biconica, n.sp. 

 (Plate ii., fig. 24.) 



Shell minute but solid, biconical, base greatly produced, peri- 

 phery keeled. Colour white. Whorls four, somewhat turreted. 

 Sculpture : first and second whorls smooth, third comparatively 

 coarsely cancellated, fourth with dense fine spiral cords crossed 

 b}^ fainter growth-lines which tend to bead the interstices. Base 

 two-thirds of the total height. Umbilicus wide and deep, bordered 

 by a conspicuous ridge, and having an elevated funicle winding 

 within. Aperture oblique, rhomboidal, channelled by the um- 

 bilical ridge, and with a gutter at the termination of the funicle. 

 A heavy outstanding varix occurs a short distance behind the 

 aperture. Height 1-7, major diam. 16, minor diam. 1 mm. 



Hah. — Torres Straits, between Cape York and New Guinea; 

 one specimen, in company with Crossea striata, Watson, dredged 

 by Mr. J. Brazier in 8 fathoms, on a sandy mud bottom. 



Type to be presented to the Australian Museum. 



The small size, produced base, and wide umbilicus are characters 

 which distinguish this from other Australian members of the 

 genus. Renewed study strengthens the conviction, which I have 

 already expressed, that Crossea is unhappily associated with Scala, 

 a,nd that it would be more appropriately ranked with Trichotropis 

 or Fossarus. 



Having examined the type of Crossea mimUa, Petterd, I am 

 unable to agree either with its author that it is a Crossea, or 



