60 HELIX-HELICOPHANTA. 



or very narrowly rimate ; the first two are finely obliquely indented 

 or wrinkled on the body-whorl and bicingulata has granulate colu- 

 mella when adult ; H. ibaraoensis is not wrinkled by oblique 

 indentations, and the columella is smooth, although the thin 

 parietal callus is granulate. If. vesicalis is remarked upon under If. 

 bicingulata. 



H. CORNUGIGANTEUM Chemnitz. PI. 14, figs. 59, 60, 61. 



Shell large, umbilicate, depressed, solid and rather thick, opaque, 

 brownish-yellow, streaked with chestnut ; surface shining, with ir- 

 regular, obliquely arcuate growth-wrinkles, and a number of incon- 

 spicuous, low, cord-like spirals, a little darker colored than the 

 ground-color ; more closely examined, the surface is seen to be 

 covered with a fine malleation or oblique wrinkled pattern ; and in 

 some places it is microscopically granulate, notably 011 the inner 

 whorls when not worn. The spire is small and very obtuse ; apex 

 minute, flat ; suture narrowly impressed. Whorls about 41, the first 

 3 of a uniform fleshy-brown color ; last whorl depressed, its last 

 third rapidly descending, rather flattened beneath. Aperture very 

 oblique, oval-truncate, bluish-white inside ; peristome white, rather 

 thick and obtuse, narrowly expanded all around, dilated and pro- 

 jecting in a rounded lobe partly over the umbilicus; parietal wall 

 with a white callus, heavy at its edge. Umbilicus rather wide, but 

 scarcely penetrating deeper than the last whorl. 



Alt. 45, greater diam. 75, lesser 58 mill. Oblique alt. between 

 basal and upper lips 40, greatest width of aperture 50 mill. 



Alt. 36 greater diam. 75, lesser, 54 mill. Oblique alt. from basal 

 to upper lip 38, greatest width of aperture 48 mill. 



Id. of Agalega, N. E. of Madagascar (teste Sir David Barclay). 



Helix cornu giganteum CHEMNITZ, Syst. Conchyl. Cab. ix, p. 247, 

 t. 208, f. 2051, 2052. PFE. Monographia i, p. 16. REEVE, Conch. 

 Icon., f. 173. 



This species may be known by its depressed form, solid texture, 

 light yellow color, streaked obliquely with chestnut, and especially 

 by the rather broad umbilicus, which is usually more than half 

 covered by the expanded lobe of the columellar lip. The parietal 

 callus shows no trace of granulation. 



The measurements given above show how the species varies in eleva- 

 tion. There is, however, but little change in the general features of 

 the shell. The umbilicus is always wide, even when nearly covered 



