126 HELIX-HADRA. 



dividuality when the entire series is seen together ; I have retained 

 them as a matter of convenience. 



Subsection HADRA (restricted). 

 Group of H. bipartite Fer. 



H. BIPARTITA Ferussac. PI. 21, figs. 43, 44. 



Shell large, globose-conoidal, narrowly umbilicated, solid and 

 strong, yellow or russet-yellow above, the suture margined by a brown 

 line, deep chocolate beneath. Surface rather smooth, but with low, 

 coarse wrinkles of growth, and under a lens showing an obscure 

 microscopic reticulation on some of the whorls of the spire. Spire 

 conical, apex somewhat obtuse ; whorls 7, slightly convex, the last 

 swollen, deflexed in front, tumid around the umbilicus. Aperture 

 oblique, whitish inside ; peristome white, expanded, reflexed, the mar- 

 gins converging and joined by a thin callus, baso-columellar margin 

 dilated half over the narrow, deep, funnel-shaped umbilicus. 



Alt. 52, diam. 60 mill. 



Cape York, Cape Direction, Cape Grenville, Daintree River and 

 Albany Island, N.-E. Australia. 



H; bipartite FER., Hist., t. 75 A, f. 1. WOOD, Ind.Test. Suppl., t. 

 7, f. 59. REEVE, Conch. Icon., f. 359. PFR. Monogr. i, p. 319 ; 

 Conchyl. Cab., p. 320, t. 56, f. 9, 10; Novit. Conch, iii, p. 494, t. 

 107, 1, 2 (varieties). Cox Monog. Austr. Land Sh., p. 54, f. 5, f. 7. 

 HEDLEY, Proc. Roy. Soc. Queensl. v, 1888, p. 57. Hadra bipartita 

 Fer. SEMPER, Reisen im Archip. Phil, iii, p. 160 (Anat.). If. semi- 

 badia ALBERS, teste Pfr. 



This is a large, solid shell, with elevated spire, and conspicuous 

 in coloration. It varies exceedingly in size ; the smallest specimen 

 before me (var. minor pi. 21, fig. 44) measuring alt. 26, diam. 31 

 mill. Specimens of a nearly uniform yellow are before me. In 

 these the base is only slightly darker than the upper surface. 



Var. SEMICASTANEA Pfr. PI. 35, figs. 1, 2, 3, 4, 5. 



Generally smaller, the entire shell more depressed. Color either 

 light russet-yellow above, chocolate beneath, or dark both above and 

 below, having a light line at the periphery. 



Alt. 35, diam. 46 mill. 



Alt. 20, diam. 28 mill. 

 Islands of Torres Sts., Australia, from Lizard Id. to Stephen's Island. 



