I-'-' OXYSTYLA, MEXICO, ETC. 



O. MEI.AXOCHEILUS ( Valenciennes). PI. 18, figs. 1, 2, 3. 



Shell rather elongate-conic, with lightly convex whorls; tawny- 

 yellow, unicolored or rarely with one or two narrow spiral bands; 

 last whorl with several narrow blackish varices; apex white. Aper- 

 ture white inside, showing a black varix or two ; peristome slightly 

 thickened, with a rather wide black-brown border. 



Alt. GO, diain. 34, aperture 28 mill. 



Alt. 50, diam. 28, aperture 21 mill. 



W. IF. Mexico: Tres J/arias /stands (Forrer, Richardson); 

 Ma.atlint ( Reigen) ; Sierra Madre (? Tonahl in Jalisco) (Xantus) ; 

 Colima (Rolle). 



. Jiiilliiins melanoc/tei/ifs VALEXC. in Ilumboldt & Bonpland's Recueil 

 d'Observ. Zool., ii, p. 24G, pi. 55, f. 3 o, l>. (1833). O/y/W/rws 

 mehinocltihis (Valenc.), v. MART, in Malak. Bliitt. xii, pp. 45, 70 



(1865) BIXXKY, Terr. Air-breath. Moll. U. S., v, p. 410, f. 287; 



Man. Amer. Land Shells, p. 440, f. 484. ROLLE, Nachrbl. D. M. Ges- 

 1895, p. 130. Ortiitir/iiis melanochilus v. MAHTEXS, Biol. Centr. 



Amer., Moll., pp. 181, 190, pi. 11, f". G. 7, 7a (1893) Knlhmts 



zebra var. e. Pi R., Monogr. Helic. Vivent. ii, p. 144. ( h-tliulicus 

 zebra (Miilh), CA I.TKNTEH, Cat. Ma/athm Shells. pp. 17(1, 177. 

 BIXM i A. UI.AMI, Land and Fresh-water Shells of N. America, i, 

 217, f. 371, p. 215, f. 3G7 (jaw). < >rt//a/i<-/is uudatus Brug., var. 

 ? = 0. melandcheilus Val., STEAKXS, Proc. I. S. Nat. Mus. xvii, 

 1894, p. 1G3. 



The more oblong body-whorl, obsolescence of the dark spiral bands, 

 and numerous blackish varices are the main features separating this 

 from O.fefUSSaci var. fricinckt, which, moreover, seems to be widely 

 separated in geographic nume from what has been M -In-ii-d as true 

 melanocheilus by Dr. von .Martens. 



It sliould lie said, also, that the selection of the Northern Mexican 

 form as the true melanocheilus is wholly arbitrary. The original 

 specimen may have been either 0. ferussaci tricincta or n. n/n/-acai- 

 f>i'/isis imitator. As to the original locality, " Valenciennes gives 

 simply ' Nouvelle Kspagne,' that is to say Mexico and Central 

 America; hi- lignre, although .-bowing distinct bands, agrees better 

 in its more elongated form with the N."\\'. Mexican species than with 

 the (Vntral American <>. /'rrnssari, var. tr/cinctiis." 



It is not known from what striped form of < >rt!tali<-its the north- 

 western inrlaiinchciliiK arose ; but probably future collections will show 



