76 



Diagnosis. Shell light amber-colour, sometimes white, smooth, glossy, strongly arched, 

 half-moon shaped, basal margin pinched in about two lines long, forming somewhat like a 

 shoulder, then slightly ventricose, from that to the apex regularl)' tapering apex with a minute 

 perforation entire. Length 28 mill.; diam. of base at shoulder 2; below i mill. (Brazier). 



Distribution. Princess Charlotte Bay, North East Australia, 13 fms, sandy mud; 

 Cape Grenville, North East Australia 20 fms, mud; York Island, Torres .Straits, 13 fms, hard 

 mud bottom; Darnley Island, Torres Straits, 5, 15, 20, 30 fms. (Chevert Exp.). 



Remarks. The lower part of this species resembles the spines of the sea-urchins 

 (Echinidae). The greater part of the specimens are encrusted over with a fine coating of coral- 

 like substance. (Braz.). 



In his Manual Mr Pilsbry adds: "Described as a Dentaikini^ the specific name being 

 preoccupied. It seems to be a Caduhis or a Ditrupa. We have not seen specimens, but the 

 last clause of Brazier's observations .suggests the latter genus". 



Afterwards Hedley published the following note with an accompanying figure : 



Cadulus laevis Brazier. The author of this species has supplied me with co-types from 

 Darnley I., Torres .Straits. The shell selected for illustration measures directly from end to end, 

 that is along the chord of the arc, 26 mm. It is exceptional in having the small end bifid; 

 most are circular and simple. A submedian constriction (marking a rest point in growth?) noted 

 in the original description is present in but few examples and varies in position. The degree of 

 curvature varies, young shells being more bent. All under the lens are concentrically wrinkled 

 throucfhout their length. 



Considering the meagre details at their disposal, Messrs Pilsbry & Sharp estimated 

 with remarkable accuracy the systematic position of the species". 



The figure looks dangeroush- like a Ditritpa but on the authority of ^Ir. Hedley it 

 is now considered to be a Caihilus. 



