178 HELIX-HADRA. 



Not known except by the original description. Pfeiffer and Tap- 

 parone-Canefri place it in Camcena, but it is more likely, if found, 

 to prove a Hadra. 



Subsection XANTHOMELON Von Martens, 1861. 



Xanthomelon MART, in ALBERS, Die Heliceen, 2te Ausgabe p. 174 

 (as sect, of Cochlostyla), type, H. pomum Pfr. VON MARTENS, Mal- 

 akozoologische Blatter, xvi, p. 77, 1869. Galaxias (in part) Cox, 

 Monogr. Austr. L. Sh. ^ 



A group of globular shells, especially characteristic of north and 

 northeast Australia. They are connected with the typical manifes- 

 tations of Hadra by such species as H. bitceniata, etc. The anatomy 

 is similar to that of Hadra and Sphcerospira. 



The species are characteristic mainly of central and north Aus- 

 tralia, comparatively arid regions in which the Sphcerospira and Ba- 

 dites sections of Hadra are but sparingly or not at all represented. 



H. POMUM Pfeiffer. PI. 38, figs. 73, 74. 



Shell nearly covered umbilicate, globose, yellow, often reddish on 

 the spire ; not spirally striated ; whorls 4 to 5 ; lip pure white, 

 narrowly expanded all around, broad and flattened at the columella. 



The shell is globular, a little depressed, pure white under the epi- 

 dermis, which is yellow, a little tinged with olive. Surface shining, 

 having oblique growth-wrinkles, and little indentations or dents in 

 places ; on the spire granulated more or less distinctly. Spire low ; 

 apex obtuse ; suture rather deeply impressed. Whorls convex, the 

 last subglobular, descending in front, a little constricted just behind 

 the lip. Aperture oblique, round-lunate, white within; lip narrow- 

 ly expanded, a little thickened within, the columella dilated into a 

 broad flat plate which partly or almost wholly conceals the umbili- 

 cus ; columellar edge bearing a blade-like callus. 



Alt. 36, greater diam. 38, lesser 34 mill. 



Arnhem Land, North Australia. 



H. pomum PFR., Symbolse ii, p. 37 ; Conchylien Cab. p. 318, t. 55, 

 f. 11-13; Monogr. i, p. 320. PHILLIPPI, Abbild. i, t. 2, f. 8. 

 REEVE, Conch. Icon. f. 362. Cox, Mon. Austr. L. Sh. p. 40, t. 4, f. 

 7. TATE, Trans. R. S. S. Austr. v, p. 49. H. urvillei Hombr. & 

 Jacq., Voy. Pole Sud, Moll., t. 3, f. 1-3. H. pseudomeadei BRAZIER 

 in Harcus' S. Austr. Hand-book (name only). And in all proba- 

 bility, H. sphceroidea LE GUILLOU, Revue Zoologique, p. 188, May, 

 1845. 



