CHLOROSTOMA. 173 



umbilicus. The aperture is less oblique than in any of the preceding 

 species of Chlorostoma. 



C. RUGOSUM A. Adams. PL 26, fig. 26. 



Shell narrowly umbilicate, conoidal, solid, heavy, dull cinereous, 

 more or less variegated by brown, blackish or red streaks; spire 

 conoidal, generally eroded and white or yellow at the apex ; whorls, 

 about 5, obliquely striate, radiately coarsely and irregularly plicate 

 and rugose above, sometimes nearly smooth ; periphery rounded ; 

 base convex, concentrically lirate ; aperture oblique ; columella 

 strongly dentate in the middle or below it, with a second small 

 tooth at the base ; edge of the columella rather deeply curved above 

 the tooth, but spreading at its junction with the whorl, bounding and 

 somewhat narrowing the umbilicus by a white callus, which does not 

 extend to the upper margin of the aperture ; umbilicus deep, white 

 within. Alt. 26, diam. 27 mill. 



L. California ; Gulf of California. 



Chlorostoma rugosum A. AD., P. Z. 8., 1851, p. 182. T. rugosus 

 FISCHER, Coq. Viv., p. 231, t. 75, f. 3. 



A rude, rugose species, like C. aureotinctum ; but much less 

 coarsely sculptured, with narrower umbilicus, different columella, 

 and parietal wall lacking the callus of that form. Var. RUFOTINC- 

 TUM Carpenter (pi. 27, fig. 30) is smaller, alt. 20, diam. 21 mill., 

 and radiately striped with lusterless red. The spiral lirulie are some- 

 times visible also upon the upper surface. 



Species of Peru and Chili. 



C. ATRUM Lesson. PL 28, figs. 40, 41. 



Shell imperforate, conical, more or less depressed, heavy, solid, 

 lusterless black ; whorls about 6, moderately convex, separated by 

 impressed sutures, smooth, except for slight incremental strise ; body 

 whorl more or less depressed, rounded or subangular at the 

 periphery ; base flattened, concave in the center, eroded and light 

 purplish in front of the aperture ; aperture- very oblique, the outer 

 lip black-margined, smooth and pearly within ; columella oblique, 

 obtusely dentate in the middle; umbilico-columellar tract covered 

 by a white callus, excavated at the position of the umbilicus, and 

 bearing a spiral rib. Alt. 35, diam 40 ; alt. 26, diam. 40 mill. 



Coasts of Chili and Bolivia. 



