OXYSTYLA, MEXICO, ETC. 129 



Var. (pi. 21, figs. 35, 36). This is the " melanocheilus form " of 

 0. boucardi, reported by Strebel. Six specimens, part of them young, 

 were collected by Sumichrast in the Cerro Negro near St. Efigenia, 

 Tehuantepec, together with "form A" (pi. 20, f. 23, 29). They 

 agree with boucardi except in wanting stripes. The separated vari- 

 ces are narrow, brown-black ; two adult and two young examples 

 show two bands weakly indicated on the last whorl. 



Var. uhdeana von Martens. PI. 23, figs. 16, 17, 18 ; pi. 22, figs. 3, 



4,5. 



Dull buff, with close, wide, continuous zigzag streaks of purplish- 

 chestnut, the last whorl interruptedly 2 or 3 banded ; apex purple- 

 black ; whorls 6Jf, but slightly convex; peristome broadly dark- 

 bordered. 



Western Mexico: State of Michoacan (Uhde). 



Orthalicus livens v. MARTENS, Malak. Blatter xii, p. 38 (1865) 

 PFR., Monogr. Hel. Viv. vi, p. 200 (note). FISCHER & CROSSE, 

 Miss. Scient. Mex., Moll., p. 453, pi. 18, f. 6, 6. STREBEL, Beitr. 

 Mex. Land- und Siisswasser-Conch. v, p. 32, pi. 11, f. 19. Ortali- 

 chus livens var. uhdeanus v. MARTENS, Biol. Centr. Amer., p. 181, 

 189 (1893). Orthalicus undatus (part), TRYON, Amer. Journ. 

 Conch, iii, pi. 13, f. 3. 



Resembling 0. longa in the broad dark varices, small aperture and 

 general form, this differs in the less convex whorls and spiral bands 

 or angulated stripes. The two specimens illustrated on pi. 22, figs. 

 3, 4, 5, were collected by Gabb, marked simply " Mexico." Another 

 individual of this lot was figured by Tryon as 0. undatus (Am. Jour. 

 Conch, iii, pi. 13, f. 3). Fig. 5 resembles Fischer & Crosse's figure 

 of '' livens," but on the back the penultimate whorl shows angulated 

 stripes like those on the last whorl of fig. 3. The latter figure cor- 

 responds well with the Michoacan specimen collected by Uhde, de- 

 scribed by von Martens and figured by Strebel. 



0. LEUCOCHILUS (Fischer & Crosse). PL 21, figs. 37, 38, 39. 



Shell ovate-conic, rather solid, longitudinally and somewhat ob- 

 liquely wrinkle-striate, but little shining; white, with ashen varices; 

 spire conic, the apex rather obtuse, suture impressed. Whorls 6^, 

 a little convex, the first two smooth, glossy, white, the last whorl 

 slightly descending, slightly longer than the spire, more strongly 

 wrinkle-striated. Aperture oblong-oval, somewhat obliquely reced- 



