496 MOLLUSCA OF MAST HEAD REEF, QUEENSLAND, II., 



Aperture entire, free, though barely so, from the body-whorl, 

 subcircular, angled above; outer lip thin, a little expanded; 

 columella arched, partly reflected over the umbilicus. Base 

 rounded. Umbilicus narrow, deep, margined by a ridge which 

 runs out to the point of the pillar. Height l'5mm.; breadth 

 1-1 mm. 



Dredged in abundance in 17-20 fathoms. The rich orange 

 colour of this minute shell readily distinguishes it. 



'&^ 



Anabathron contortum, n.sp. 

 (Plate xvii., fig. 21.) 



Shell minute, first columnar, then untwisted. Whorls five, of 

 which the last three are adult. Protoconch of two flat whorls 

 terminating in a heavy varix and angled by a thick upstanding 

 spiral marginal keel, the whole resembling a Liotia minima, and 

 causing the summit of the shell to be sharply obliquely truncate. 

 From the protoconch the adult shell descends almost perpendicu- 

 larly, first two whorls tightly coiled but long drawn out, the 

 final polygonal, unscrewed and long drawn out. Colour 

 uniform ochre. Sculpture: each whorl bears on base and shoulder 

 a heavy spiral keel which defines an angle in the contour of the 

 whole shell; in the penultimate the lower keel is buried by the 

 succeeding suture of the next whorl. Fine, close, longitudinal, 

 lamellate riblets traverse every whorl and render the spiral keels 

 delicately nodose; ver}^ faint but dense spiral strife cross the 

 riblets. Aperture subcircular, with a broad, thick continuous 

 varix-rim. Height 1-24 mm.; breadth 0-5 mm. 



Two specimens in 17-20 fathoms. 



In size and sculpture this is comparable with the type of the 

 genus, A. co7itahidatum, from which the colour, protoconch and 

 irregular disposition of the coils plainly separate it. 



Anabathron ascensum, n.sp. 



(Plate xvii., fig. 20.) 



Shell subulate, very solid. Whorls five, first trochiform, 

 suddenly descending to form the tightly twisted, long drawn coil 



