MONODONTA. 113 



M. TIGRIXA Chemnitz. PL 23, figs. 61-64. 



Shell conoidal, more or less elevated, imperforate, lusterless black- 

 ish or purplish, unicolored or with a few scattered white dots, or 

 yellowish flexuous lines ; spire conic, apical whorls eroded, yellow or 

 whitish; whorls about 6, spirally coarsely but obsoletely lirate; 

 aperture large, oblique, black-bordered,, silvery within; columella 

 simple, white or yellowish, bordered by a dull purplish streak ; parie- 

 tal wall usually covered by a thin silvery callous. 



Alt. 27, diam. 32 mill. 



Cape Region, S. Afi-'n-u. 



Trochus tigrinus CHEMNITZ, Conchyl. Cab., v, p. 53, f. 15HO. 

 PHILIPPI, Conchyl. Cab., p. 27, t. 6, f. 5. FISCHER, Coq. Viv., p. 

 174, t. 58, f. 1. 



In form like M. merula ; but without the rosy base, more coarsely 

 and obviously spirally lirate, and usually dotted with white. 



Var. YASCOI Fischer. PI. 23, figs. 62. 



Shell with acute spire ; deeply spirally sulcated, the penultimate 

 whorl five-lirate ; aperture less dilated. Alt. 33, diam. 31 mill. 



M. SAUCIATA Koch. PI. 24, figs. 95, 96 ; pi. 21, figs. 31, 32 ; pi. 62, 

 figs. 81, 82. 



Shell low-conical, imperforate, rather thin ; ground-color greenish, 

 especially on the last whorl, usually purplish on the spire, and either 

 (1) spirally encircled by bands of dark green, black, or red oblong 

 spots articulated with a lighter color, or (2) obscurely mottled with 

 reddish, the ground-color covered with fine oblique or zigzag lines ; 

 the pattern sometimes so obscurely mottled, spirally and obliquely 

 streaked, that it appears nearly uniform olivaceous, especially on the 

 last whorl ; spire more or less elevated, conic, the apex minute, 

 acute, reddish, when not eroded ; sutures well impressed ; whorls 6, 

 spirally more or less obviously, finely, irregularly striate or lirate; 

 body-whorl rounded or subcarinated at the periphery ; base some- 

 what convex, more or less impressed around the axis, sometimes 

 eroded in front of the aperture; aperture large, very oblique; outer 

 lip with a black-spotted green edge, which is generally followed by 

 a broad thin opaque-white band, within which it is nacreous and 

 iridescent ; columella oblique, thin-edged, the edge convex in the 

 middle ; columellar area white, more or less eroded ; umbilical tract 

 covered by a thick pad of enamel. Alt. 20, diam. 24 mill. 



Madeira; Mogador ; X.Spain; Cape Verde Is. ; Canary Is. 

 8 



