136 OXYSTYLA, SOUTH AMERICAN. 



the external markings in lilac ; peristome narrowly edged with chest- 

 nut ; columella concave or nearly straight, white, thin; parietal 

 callus rather thin, chestnut-colored, often in part wanting. 



Alt. 44, diam. 26, longest axis of aperture 27 mill. 



Alt. 51, diam. 30, longest axis of aperture 31 mill. 



Eastern Brazil : Province of Para (Spix's type locality); Pernam- 

 buco (Moricand); Bahia (Blanchet, von Ihering, et at.). Southwest- 

 ern Brazil : Corumbd, prov. Matto Grosso (H. H. Smith, Germain). 

 Dutch Guiana or Surinam (Cuming coll.). Venezuela : Barcelona 

 (C. Blume). 



Achatina pulchella SPIX, Testae. Brasilia pi. 9, f. 2 (legend at 

 foot of plate) (1827) Bidimus pulchellus PFR., Monogr. ii, p. 144; 



iii, p. 389 Orthalicus pulchellus BECK, Index Moll., p. 59. 



SHUTTLEWORTH, Notitise Mai., i, p. 62, pi. 4, f. 6, 7. PFR., 

 Monogr. iv, p. 588, vi, p. 199 ANCEY, Journ. of Conch, vii, p. 94. 

 Bulimus undatus WAGNER, in Testae. Bras., p. 9. Helix undata 

 var. FER., Hist., pi. 117, f. 1. Orthalicus zigzag BECK, Index Moll., 

 p. 59 /? Bulimus zigzag LAMARCK, An. s. Vert, vi, 2d part, p. 

 118, no. 4 (1822); Edit. Deshayes viii, p. 223. 



The typical form (pi. 28, figs. 27, 28, 29) appears at Para and 

 Pernambuco ; the variety at Bahia (figs. 36, 37) and in Venezuela 

 (figs. 34, 35). In Surinam the shells are nearly typical in coloring, 

 according to Shuttleworth's figures. I have not seen specimens from 

 Matto Grosso, and do not know what form of the species occurs there. 

 Figs. 30, 32, 33 are drawn from specimens labelled "Amazon River." 



It is a beautiful species, very easy to recognize when typically de- 

 veloped (figs. 28, 29) by its crowded, narrow, dull purplish stripes, 

 intersected by three narrow girdles, on a buff-fawn ground. 



By coalescence of some of the stripes at the positions of the bands, 

 triangular blotches separated by cream tinted intervals are sometimes 

 developed (fig. 27). 



The young (figs. 30-33) has less crowded, wider and more angu- 

 lated stripes and continuous or subcontinuous girdles, assimilating to 

 the ancestral type of the whole group. There is generally an almost 

 white band below the peripheral girdle, and below the basal another, 

 the latter bounded below by a circum-columellar dark band which 

 does not occur in other species of the Zebra group, and is obsolete in 

 adults of pulchella. The bands are dark brown within the mouth, 

 the streaks a little lighter, and the white markings alluded to are 

 very distinct. 



