20 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



and slightly expanded; inner lip almost vertical, expanding at the 

 base into a callus which fuses with the thin callus that covers the 

 parietal wall; partly reflected over the narrow umbilicus. 



The type, Cat. No. 244690, U.S.N.M., was collected by Lieut. Col. 

 Edgar A. Mearns on Mount Apo, Mindanao. It has 6.5 whorls and 

 measures — length, 59 mm. ; diameter, 28.3 mm. 



AMPHIDROMUS BASILANENSIS, new species. 

 Plate 9, fig. 3. 



Shell of medium size ; elongate-ovate. The first three whorls dingy 

 white with a satiny luster, the remaining of the same ground color, 

 marked at irregular intervals by more or less interrupted axial zigzag 

 lines of light brown which have no definite form of disposition. The 

 brown markings become more abundant on the last whorl. The 

 whorls are moderately well rounded, appressed at the summit, and 

 crossed by fine, very retractive axial lines of growth and exceedingly 

 fine spiral striations. Sutures moderately constricted. Aperture 

 moderately large, oval; outer lip thickened and reflected; inner lip 

 thickened, somewhat sinuous and reflected over the umbilical chink; 

 parietal wall covered with a moderately thick callus. The inside of 

 the aperture shows the same coloration as the exterior, the brown 

 markings extending through the shell. The outer edge of the peris- 

 tome is white, while its inner border is of the same brown as the 

 longitudinal bands. 



Two specimens of this species were collected by Mr. McGregor, of 

 the Philippine Bureau of Sciences, on Basilan Island. One of these, 

 the type, is in the United States National Museum, Cat. No. 244691 ; 

 the other is in the Philippine Bureau of Sciences. The type has six 

 post-nuclear whorls and measures — length, 45.8 mm.; greater diam- 

 eter, 24.2 mm. 



AMPHIDROMUS FLORESI, new species. 



Plate 8, fig. 3. 



Shell ovate, sinistral. Early whorls well rounded, with a narrow 

 band of gray immediately above the suture, the rest white. The suc- 

 ceeding turns are evenly rounded, appressed at the summit, and very 

 feebly constricted at the sutures. All but the last one and a half 

 turns are marked by faint lines of growth and exceedingly fine, spiral 

 striations. On the last turn and a half, the axial sculpture becomes 

 much strengthened, forming regular threadlike riblets. The shell 

 is of bluish white ground color, marked with irregularly distributed, 

 somewhat wavy, narrow, brown axial bands. These may be con- 

 tinuous from the summit to the umbilical region or interrupted. In- 



