108 HELIX-CHAROPA. 



Whorls 5, the earlier enrolled within the later and almost con- 

 cealed by them. From the channelled suture the last whorl rises 

 perpendicularly, then arches outwards to its summit, from which it 

 describes a curve of a third of a circle to its base, whence it incurves 

 to the umbilical crater. The characteristic involute growth does 

 not occur till the shell has attained a whorl and a half, at which 

 point the embryonic sculpture is interrupted (as described in alban- 

 ensis) by the adult and the shell at once commences to widen axi- 

 ally ; viewed either from above or beneath, the smoother plane 

 embryonic shell is seen as the flat floor of the spiral or umbilical 

 pit. Sculpture: the last whorl is adorned with 150 sharp erect 

 straight costae, which are seen to stand out in profile on the periph- 

 ery like the teeth of a circular saw ; they are directed straight across 

 the whorl from the spiral to the umbilical sutures and may be 

 likened to the lines of longitude on a terrestrial globe. The sec- 

 ondary sculpture varies upon different parts of the shell, that 

 sketched in the accompanying illustration is selected from the 

 umbilical wall of the last revolution. Upon the spire two or three 

 raised hair-lines parallel to the costse occupy the intercostal spaces, 

 at right angles similar hair-lines cross both these and the costse, 

 producing a reticulated appearance. Towards the periphery these 

 spiral lines grow faint, while the intercostal lines multiply to half a 

 dozen, within the umbilicus the transverse lines diminish and the 

 spiral sculpture assumes the supremacy. Umbilicus cup-shaped, 

 profound, exposing every revolution, a third of the shell's diameter 

 in width. Aperture perpendicular, crescentic, peristome straight, 

 sharp, scarcely reflexed on the columellar margin, projecting at the 

 periphery past an imaginary line drawn from insertion to insertion. 

 Callus smooth, shining, thick, semitransparent, quite burying the 

 overtaken costse, projected on the penultimate whorl in advance of 

 the peristome. Diam. maj. 2$, min. 21, alt. 1J mill. (Hedley.) 



Gad's Hill and Mount Bischoff, Tasmania (Beddome) ; occurred 

 under timber. 



Helix antialba BEDDOME, Monograph of the Land Shells of Tas- 

 mania p. 41 ; Proc. Roy. Soc. Tasmania 1879, p. 23 ; SUTER, Trans. 

 N. Z. Inst. xxii, 1889, p. 226. Charopa antialba HEDLEY, Proc. 

 Linn. Soc. N. S. Wales 1892, t. 1, f. 5-8. 



The type is in the collection of C. E. Beddome, Esq., R. N. The 

 above description and the figures are from advance proofs of an 

 article by my friend, Charles Hedley. 



