12 THE NAUTILUS. 



moderately raised, conoidal spire, distinctly angular periphery and 

 convex base. Uniform chestnut colored. Striatulate and densely 

 though indistinctly granulate, the granules elongated in the direction 

 of growth-lines. Whorls 5^, slowly increasing, the last angular at 

 the periphery, slightly descending in front. Aperture oblique, 

 rounded-lunate, the peristome slightly expanded. Alt. 7-^, cliam. 

 \()~ mm. Prov. Tonga (Gaines). 



Ganesella Jacobii n. sp. Shell rather narrowly umbilicate, semi- 

 glol)ose, thin, pale yellowish corneous ; surface stria tu late, decussated 

 with incised spiral lines; spirt? convexly conoidal ; whorls 5^, slowly 

 increasing, the last one very indistinctly angular at the periphery in 

 front, becoming rounded on the latter half, convex beneath, exca- 

 vated around the narrow umbilicus. Aperture oblique, lunate, the 

 peristonie narrowly expanded, white, base-columellar margin reflexed. 

 Alt. 13^, diam. 18^ mm.; umbilicus slightly over 1 mm. wide. 



Cyclolus (?) micron, n. sp. Shell very minute, somewhat discoidal, 

 with low conoid spire and widely open umbilicus; composed of 3^ 

 tubular whorls, separated by deep sutures, the last one barely in con- 

 tact with the preceding at the aperture ; pale corneous, subtranslu- 

 cent, with delicate growth-striae. Aperture circular, vertical, the 

 peristome simple and thin, continuous. Operculum lodged at the 

 edge, presenting a densely concentrically lamellose external face, the 

 center deeply sunken. Alt. '-\, diam. 1.0 mm. 



Pou/dttopsis Hirasei, n. sp. Shell perforate, t!irreted,in shape re- 

 sembling Pomatiopsis californicns Pils.; general color pale yellowish 

 green, produced by buff stivaks and lines on a light green ground ; 

 surface nearly smooth. Whorls remaining 5 (the earlier being 

 eroded or decollate), quite convex, separated by deep sutures. The 

 last third of the last gyration of the suture does not descend as much 

 as the preceding turns, giving the effect of a slightly ascending whorl 

 toward the mouth. Aperture ovate, subangular above, the outline a 

 little flattened on the parietal margin ; peristome simple, continuous, 

 black-edged ; the columellar margin arcuate, a little thickened and 

 perceptibly dilated. Alt. 9, diam. 4.8, longest axis of aperture 3.6 

 mm. Operculum ovate, brown, the cicatrix oblong, large, occupy- 

 ing the inner half of the inside face, its edge raised. 



I at first thought to place this species in the Realiida; but on ex- 

 amining the radula, I found it could belong neither to that family 

 nor to the Assiminiidte, the dentition being far nearer that of Poma- 

 tiopsis. The formula of denticles is 3 t , 5, 6, <>. The median den- 



-j L 



tide in the central and ad median teeth is larger than its fellows. 

 This radula differs from that of the American Pomatiopses in having 

 two, instead of one, basal denticles on each side of the central tooth. 

 See NAUTILUS XII, 127 ; X, 37, for information on the American 

 species. 



