50 



RECORDS OF THE AUSTRALIAN MUSEUM. 



Around the umbilicus are three spiral cords. Aperture oblique, 

 angled above, rounded below, outer lip neither thickened nor 

 reflected. Umbilicus deep, narrow, contracted by the columella. 

 Major diam., 1*75 mm.; minor diam., 1'37 mm.; height, 1-5 mm. 

 A single sjiecimen occured. 



Adeorbis axgulata, sp. nov. 

 (Fig. 1.5). 

 Shell of moderate size, surface dull. The summit a Hat expanse, 

 from which the protoconch and fii'st whoi'l project, and which is 

 bounded by an angle or spiral rib, whence the side descends per- 

 pendicularly. A similar keel occurs where the side meets the base, 

 and a third margins the wide concave umbilicus. Colour, pale yel- 

 low. AVhorls four and a half, rapidly increasing. Sculpture, some- 

 what like that of Vanikm\h The first adult whorl has strong 

 spaced radial lamellate ribs which gradually fade away with the 

 increase of the the shell, but which persist longest as scales 

 upon the keels. Fine, irregular growth lines occur on the 



Fi^. 15. 



Adeorbis (mgulata. 



last whorl. Spiral sculpture absent. Aperture oblique, rhom- 

 boidal, lip thin. The type is 3"65 maj. diam.; 2-5 min. diam. 

 2-0 mm. height, but a fragment of a larger individual indicates 

 that the species forms another whorl, and attains a height of 6 mm. 



There are but three species of the genus reported from Australia, 

 A. angasi, from New South Wales, A. vincentina, Angas, from 

 South Australia, and A. plana, A. Ad. i^A. siyaj-etiniis, Pilsbxy) 

 from Queensland. 



The keeled whorls readily distinguish the novelt3'from A. angasi, 

 which it approaches nearest. 



