HELIX-OBBA. 227 



chestnut band above and one below; but often a fainter subsutural 

 band is developed. The band on the upper surface ascends to with- 

 in about 1} whorls of the apex, and between it and the suture, on 

 the antepenultimate whorl the surface is lilac or purple. Apex 

 plane. Whorls 4, the last deeply descending in front, convex 

 beneath. Aperture subhorizontal, oval, white and banded within ; 

 peristome expanded, white; basal lip reflexed, partly concealing 

 the umbilicus. Alt. 132-14, greater diam. 22-25, lesser 18-20 mill. 

 Samar ; Catbalogan ; Eastern Mindanao ; Basilan ; and Leyte, 

 Philippine Is. 



H. bigonia FER. Hist., t. 70, f. 2. PHILIPPI, Abbild., i, p. 78, t. 

 4, f. 7 PFR. in Conchyl. Cab., p. 330, t. 58, f. 13, 14; Monogra- 

 phia, i, p. 334. REEVE, Conch. Icon. f. 105. HIDALGO, Jotirn. de 

 Conchyl. 1887, p. 98. H. tamarensis PFR. P. Z. S. 1842, p. 87. 

 Lucerna bizonia ADS. Obbina bigonia SEMPER, Phil. Archip. 

 Landmoll., p. 127. 



More elevated than the allied toothless species ; white, with two 

 or three brown bands and a purple streak on the antepenultimate 

 whorl. 



H. MARGINATA Miiller. PL 57, figs. 4, 5, 6. 



Shell umbilicated, depressed, lens-shaped, acutely carinated, hav- 

 ing three chestnut bands above, two below, on a whitish or light- 

 brownish ground. Surface lightly obliquely striated, showing when 

 highly magnified a texture like that produced by pressing fine cloth 

 upon plastic clay. Outer 2 -1 whorls banded, the next inner one 

 with a brown streak. No trace of a tooth on the basal lip. 



The shell is rather thin, solid, low-conoidal above, feebly convex 

 below ; carina acute, white, three bands above, two below ; apex 

 plane. Whorls 4J, the last abruptly deflexed in front, a trifle con- 

 stricted behind the basal lip. Aperture subhorizontal, white with 

 bands within ; peristome expanded, white, continued in a cord of 

 callus, across the parietal wall ; basal lip regularly curved, reflexed, 

 with no trace of a tooth. 



Alt. 12, greater diam. 261, lesser 21} mill. 



Alt. 10, greater diam. 21 mill. 



Isl. Camiguin ; Pta. Malimono near Surigao, and around Zambo- 

 anga, Isl. of Mindanao, Philippines. 



H. marginata MULLER, Hist. Verm, ii, p. 41. PFR. in Conchyl. 

 Cab. p. 69, t. 78, f. 7-9 ; Monogr. i, p. 395 ; v, p. 405. REEVE, 



