OXYSTYLA, SOUTH AMERICAN. 137 



Shuttleworth examined the radula and jaw, stating that the latter 

 is composed of 22 segments. 

 Var. prototypus n. v. PI. 28, figs. 32-37. 



Stripes on the median portion of the last whorl having a tendency 

 to become broad, irregular, interrupted; the girdles composed mainly 

 of arrow-shaped or wedge-shaped rather large spots ; markings 

 blackish-purple. 



Bahia, Brazil ; Barcelona, Venezuela. 



0. pulchellus var. /? SHUTTLEWORTH, 1. c. Helix undata MORI- 

 CAND, Mem. sur les coq. terr. et fluv. de Bahia, in Mem. Soc. Phys. 

 et d' Hist. Nat. de Geneve vii, p. 423. 



This is an earlier, less differentiated form of the species, of which 

 typical pulchella is an extreme and more local development. It is 

 more widely distributed than the typical form, occupying the north- 

 western and southern peripheral portions of the range of the species. 



Figs. 36, 37 represent Bahia specimens not quite mature. Figs. 

 34, 35 are drawn from Barcelona, Venezuela, examples. The young 

 of this form sometimes lack the cream-white sub-peripheral and basal 

 bands, or have them but faintly developed. The apex has a large 

 dark spot; the subsutural puckering may be either strongly developed 

 though short, or almost wholly wanting ; and in the specimens before 

 me there is a single dark varix or none. The parietal wall is only 

 lightly washed with chestnut; the markings are not so dark as in 

 Bahia specimens, and the ground-color is browner. 



That the Venezuelan specimens approach certain form of 0. mara- 

 caibensis Pfr., there can be no doubt ; but there does not seem to be 

 an actual intergradation. The general tone of color is much browner, 

 not pinkish or white, and the young are differently marked. 



Possibly Strebel's 0. prmceps form E, from the Amazon (Beitr. 

 Mex. Land- und Siisswasser-Conch. v, p. 16, pi. 3, f. 5) is identical 

 with this variety. It measures 40 to 50 mill, long, with 6| to 7 

 whorls. The largest specimen of prototypus before me is 45^ mill, 

 long, with 6^ whorls. 



O. MARACAIBENSIS (Pfeiffer). PI. 29, figs. 40-46; pi. 30, figs. 



49-57. 



Shell of the usual ovate form, thin but moderately solid, irregularly 

 wrinkle-striate and with very fine, shallow, partially obsolete spiral 

 striae; nearly lusterless ; no noticeable cuticle. Typically white, of 



