744 STUDIES ON AUSTRALIAN MOLLUSCA, xii., 



Zafra debilis, sp.iiov. 

 (Plate Ixxxiii., figs. 70, 71.) 



Shell small, thin, slender, conical. Colour fawn with an 

 opaque white zone median on the last whorl, and supersutural on 

 the spire; sometimes there is also a white subsutural band, the 

 white being plainer on the ribs than on the interstices. Whorls 

 seven, gradate. Sculpture : first three whorls smooth, remainder 

 radially ribbed Ribs prominent, broad, vertical, spaced by 

 about their breadth, continuing to the grooving at the base and 

 to the aperture, discontinuous from whorl to whorl, amounting 

 to fourteen on the last whorl. A slender subsutural cord con- 

 nects the tops of the ribs; beyond the ribs on the exterior 

 extremity are eight, fine, spiral striae. Aperture narrow, vertical, 

 a little sinuous, contracted posteriorly, inner lip with a free 

 elevate edge, outer lip simple, canal short, bent rather sharply 

 backwards. Length, 33; breadth, 1*1 ram. 



Hab. — Many specimens dredged, by self, off the Hope Islands, 

 North Queensland, in 5-10 fathoms; and one by Mr. A. XJ. Henn, 

 off Cape Sidmouth, N. Queensland. 



Z. phaula Melvill & Standen, from Karachi (Proc. Zool. Soc, 

 1901, p. 405), is similar in general appearance, but Z. debilis is 

 more contracted anteriorly, and has a different colour-pattern, 



Zafra atkinsoni Tenison- Woods. 

 (Plate Ixxxiii., fig.72.) 



It was briefly observed by Tryon,* under the heading of 

 Columbella speciosa Angas, that ''■ Mangelia atkinsoni Tenison- 

 Woods, is a synonym." But the name published by Tenison- 

 Woodsf appeared on 21st March, 1876, and that of Angas j on 

 1st June, 1877, so that Zafra atkinsoni must take precedence. 



Though the two appear to intergrade, the forms which received 

 these names are not identical, and, in a varietal sense, the name 

 of Angas deserves to be maintained. 



* Tryon, Man. Conch., v., 1883, p.71. 



t Tenison- Woods, Proc. Roy. Soc. Tasm., 1875, p. 141. 



:J: Angas, Proc. Zool. Soc, 1877, p.35, PI. v., fig.3. 



