220 HELIX-OBBA. 



ing clear-yellow, hydrophanous, triangular spots; spire flatly con- 

 vex, with broad, blunt apex. Whorls 4, almost flat, all of them 

 acutely keeled, causing the suture to appear narrowly margined ; 

 the last whorl suddenly falling in front, flatly convex beneath, a lit- 

 tle impressed in front. Aperture horizontal, narrow, angular-ellip- 

 tical ; peristome simple, white, the margins approaching, connected 

 by a thin callus, upper margin expanded, basal shortly reflexed, 

 suddenly arcuately ascending at the moderately wide, deep umbilicus. 

 Alt. 9, greater diam. 25, lesser 20 mill. (Pfr.) 



Islands of Luzon and Zebu ; Boac and Sta. Cruz, Marinduque, 

 Philippines. 



H. gallinula PFR. P. Z. S. 1845, p. 40 ; Monogr. i, p. 396 ; Con- 

 chylien Cab. p. 438, t. 152, f. 4-6. REEVE, f. 130. PHILIPPI, 

 Abbild. etc., i, Helix, p. 153, t. 5, f. 5. HIDALGO, Journ. de 

 Conchyl. p. 103, 1887. Obbina gallinula SEMPER, Archip. Phil., 

 Landmoll., p. 128. 



I have not seen this species. PfeifFer mentions two varieties : (1) 

 /?, smaller, base obliquely rugulose, aperture laterally less dilated, 

 and (2) g, marked all over with impressed oblique lines, becoming 

 subconcentric around the umbilicus; bands obsolete. It may be 

 compared with H. listeri, but the basal lip is not toothed. The 

 sculpture separates it from H. marginata. 



H. PLANULATA Lamarck. PI. 55, figs. 51, 52, 53, 54. 



Shell umbilicated, depressed, lens-shaped, obtusely keeled, some- 

 times scarcely perceptibly so ; whitish with a brown band above 

 and one below, interrupted by oblique, opaque, white streaks ; per- 

 istome continuous, basal lip more or less obviously toothed in the 

 middle. 



A species closely allied to JET. listeri, but less acutely carinated, the 

 surface nearly smooth, not malleated. Spire varying much in 

 degree of elevation. Whorls 5, slightly convex, the last abruptly 

 deflexed in front, constricted behind the basal lip. Aperture hori- 

 zontal, dark inside ; peristome white, broadly expanded, basal mar- 

 gin reflexed, having a slight swelling or a distinct square tooth in 

 the middle. Umbilicus cylindrical, one-tenth to one-ninth the diam. 

 of the shell. 



Alt. 13, greater diam. 30, lesser 24 mill. 



Alt. 12, greater diam. 32, lesser 25 mill. 



Alt. 15, greater diam. 26, lesser 21 mill. 



Island of Luzon ; Islet of Corregidor, near Manilla ; Marinduque; 

 Mindoro, Philippines. 



