CALLIOSTOMA. 341 



C. BICINGULATUM Lamarck. Vol. X, PL 41, fig. 29. 



Shell imperforate, acute-conical, pale yellowish or brownish, 

 maculated with white ; whorls 7 to 8, the embryonic smooth, fol- 

 lowing radiately heavily striate ; separated by impressed sutures ; 

 whorls depressed above, spirally cingulate ; cinguli 4, the upper 2 

 minute, lower 2 more prominent, with profound inters:ices ; last 

 whorl bicingulate in the middle, a little convex beneath, and 

 encircled by about 12 concentric line, white and reddish articulated. 

 Aperture rhomboidal ; columella oblique. 



Alt. 15, diam. 17 mill, (Fischer.) 



Cape of Good Hope. 



Tr. bicingulatus LAM., An. s. Vert, vii, p. 27. DELESSERT, Kec. 

 de Coquilles, t. 35, f. 1. PHILIPPI, Conch yl. Cab., p. 87, t. 15, 

 f. 8. FISCHER, Coq. Viv., p. 198, t. 64, f. 2. TV. vinctus PHIL., 

 Abbild., i, Trochus t. 1, f. 8. (?) Zizyphinus bieingulatus Lam., 

 REEVE, Conch. Icon., f. 20. 



C. UNICUM Dunker. PI. 16, figs. 10, 5. 



Shell conical, solid, imperforate, brownish-yellow, with chestnut 

 maculations above, and a brown-articulated peripheral girdle, the 

 base generally not marked. Surface of the whorls encircled by 

 numerous unequal lirse, slightly crenulated by regular incremental 

 line?, line about 9 in number on the penultimate whorl, 12-14 on 

 the base ; spire rather short, low ; apex acute, red or purplish ; 

 whorls 7, slightly convex, with a more or less obvious angle or 

 carina in the middle of the upper surface ; the last whorl sub- 

 angular or rounded at the periphery, convex beneath. Aperture 

 oblique, rhomboidal, the lip very much thickened within ; columella 

 oblique, concave above, cylindrical, with a groove marking the 

 place of the umbilicus. 



Alt. 20, diam. 21 mill. ; alt. 17, diam. 18 mill. 



Nagasaki, Decima, and Simoda, Japan. 



Trochus unicus DUNKER, Mai. Blatt., 1860, p. 238 ; Moll. Jap., 

 p. 23, t. 3, f. 3. LISCHKE, Jap. Meeres Conchy!., iii, p. 64. 

 FISCHER, Coq. Viv., p. 338, t. 105, f. 2. Calliostoma affinis DALL, 

 Amer. Journ. Conch., vii, p. 125, t. 15, f. 14. Zizyphinus unicus 

 Dkr., REEVE, Conch. Icon., f. 8. 



May be recognized by the numerous low riblets, very obsoletely 

 bicarinated form, very thick lip, etc. The C. affinis of Dall (fig. 5) 

 is the same as Dunker's typical form of unicum, figured in Mollusca 



