132 OXYSTTLA, SOUTH AMERICAN. 



clouded in't/i /iy/iter, and with wide, ill-defined bluish or olive-green 

 streaks behind (hf extremely narrow l>l<t<-h-!sh ra rices; entire last whorl 

 sometimes without light flames or stripes. Varices narrow, two or 

 tliree on the last whorl, one or two above it. Surface with fine, 

 irregular spiral stria; and some shallow coarser furrows, somewhat, 

 hut finely, mallcatcd ; plicate below the sutures, and sometimes shal- 

 lowly *o on the body whorl generally. "Whorls 6^, slightly convex. 



Aperture oblique, pure white or purple-tinted inside, often showing 

 dark stripes at the positions of the varices ; peristome obtuse, unex- 

 panded, olivaceous-bordered outside, with a blackish border within, 

 <hading into violaceous. Parietal callus strong, black ; coluniella 

 heavy, vertical, straight, truncate or subtruncate at base, white or 

 white-edged. 



Alt. 07, diam. 38, longest axis of aperture 3G mill. 



Alt. f>3, diam. 37, longest axis of aperture l\4\- mill. 



Alt. ;"* 7 -.',-, diam. 31. V, longest axis of aperture 31 mill. 



Ilnliiint unknown. 



Orf/ndicns decolor STREKEL, Beitr. Mex. Land- und Siisswasser- 

 Concli. v, p. 37, pi. 7, f. 2, 3, 4 (18M',. 



One of Strebel's specimens was labeled "Bulimw mars, Costa 

 Rica." Those in the collection of the Academy have borne the same 

 specific name, with the localities " Ecuador" and " Brazil;" but I 

 attaeh ii" weight whatever to these data. Similar to O. mnr* in 

 general features, this species differs markedly in the straight, vertical 

 coluniella, without a fold above. 0. ponderosa I have not seen, and 

 it is not unlikely that decolor may prove to be a form of that species. 

 The differences do not seem to be great. 



Sotitli Aint'riciin S/it'cies. 



A. Longest axis of aperture exceeding half the length of the shell; 

 coluniella concave or straight. 



A. Ventrieose, with pairs of yellow lines forming large /ig- 

 x.ags; whorls ;".', ; alt. ;~>0-f)7 mill. A//////////V////, p. 143 



//'. Ovate-COnic, Uniform whilish or with three liand>. no lon- 

 gitudinal tlames. maraeaibensis lorm iinitutnr, p. 1-ln 

 // ". ^\"itll longitudinal flames. 



c. Large, alt. .'iC.-Tirt mill., with inflated liody-whorl ; 

 spire flamed, the ];i>t \\horl brown with obscure or 

 sub-obsolete llammulation, spiral bands inconspicii- 



