184 HELIX-RHAGADA. 



color, and having the aperture livid brown instead of white. This 

 species has hitherto been obtained only from Port Essington, whilst 

 H. pachystyla is widely distributed throughout Queensland. (An- 

 gus.) 



H. PACHYSTYLA Pfeiffer. PI. 38, fig. 63. 



Shell globular, imperforate, yellow with numerous oblique brown 

 streaks crossing the whorls ; obsoletely spirally striated ; whorls 5? ; 

 lip pure white, blunt, not at all expanded except on base and at the 

 columella, which is reflexed in a broad flat plate, adnate over the 

 umbilicus. 



The shell is globose with conoidal spire ; surface obliquely striate, 

 decussated above by subobsolete spiral incised lines. The last whorl 

 is deflexed in front ; aperture oblique, its inside and the lip pure 

 w r hite ; columella oblique, broad, its inner edge straight or a little 

 convex ; it continues in a gracefully curved white callus across the 

 body-wall, joining the posterior termination of the outer lip. 



Alt. 40, greater diam. 38, lesser 33 mill. 



Alt. 31, greater diam. 29 mill. 



Queensland, all along the coast. 



H. pachystyla PFR. P. Z. S. 1845, p. 71 ; Monogr. Hel. Viv. i, p. 

 19 ; Kiister's Conchyl. Cab., p. 429, t. 150, f. 7. Cox, Mon. Austr. 

 L. Sh., p. 40, t. 6, f. 8. VON MARTENS Mai. Bl. xvi, 1869, p. 77, 

 with var. Daineli. SEMPER, Reisen in Archip. Phil., Landmoll. iii, 

 p. 160, t. 17, f. 22 (Anatomy). HEDLEY, Proc. Roy. Soc. Queensl. 

 1889, p. 121, t. 8 (Anatomy.) 



Differs from H. pomwn as indicated under that species. It is the 

 most abundant and widely distributed Xanthomelon. There is much 

 variation in size and in the development of spiral sculpture. 



Von Martens describes a small form as Var. ddmeli as follows : 

 Smaller (diam. maj. 33, alt. 32 mill.) ; aperture more elongated, col- 

 umellar margin proportionally long, blade-like, projecting into the 

 aperture, so that the dimensions of the mouth some distance within 

 the lip are as long as broad, while in the normal form it is broader 

 than long. Color darker, more brownish, the darker streaks less 

 conspicuous. 



Cape York. 



Section III. RHAGADA Albers, 1860. 



Rhagada ALB. Die Heliceen, 2d edit., p. 108. Type, H. reinga 

 Gray. 



