OXYSTYLA, SOUTH AMERICAN. 135 



199 (1887). 0. zebra H. & A. ADAMS, Gen. Rec. Moll, ii, p. 154, 

 pi. 75, f. 6 a. 



The full body-whorl, short, strictly conic spire, with the flamed 

 upper, and brown clouded last whorl, are characteristics of this spe- 

 cies, which is better defined than most of the princeps group. The 

 variations in color-pattern are well shown on the plate. 



Central American examples referred here by authors on that fauna, 

 are distinct from the South American shell, and in fact not closely 

 related. See under 0. princeps var. deceptor. 



Figures 31, 32 are copied from Shuttleworth's original illustrations. 

 Figs. 35, 36 are specimens from Pto. Cabello, and fig. 34 represents 

 an unusually boldly marked shell from Caracas, where the species 

 does not attain so large a size as around Puerto Cabello. 



The young of typical obductus (pi. 25, fig. 33) has, as Shuttleworth 

 remarks, some resemblance to 0. pulchella, showing numerous nar- 

 row parallel dusky stripes, bent or anastomosing at the positions of 

 the three spot-bands, on a yellow ground. As a general rule, no 

 varices are formed until near or at the end of the next-to-the-last 

 whorl. 



According to Semper, the penial accessory gland is so small and 

 so united with the penis that it is hardly noticeable. This is quite 

 different from the well-developed gland in 0. princeps. 



O. TULCHELLA (Spix). PL 28, figs. 27-37. 



Shell ovate-conic, rather thin but usually moderately solid, nearly 

 smooth, the lines of growth hardly or not visible to the naked eye, 

 with rather coarse, low, short folds below the suture, and fine, crowded 

 superficial microscopic spiral lines. Surface lustreless, often with a 

 velvety dullness. Variceal streaks narrow, brown, generally a single 

 one developed, but sometimes none, or in some old shells a number 

 appearing on the latter half of the last whorl. Flesh-tinted under a 

 thin light yellow cuticle, marked with narrow, crowded, equal, purple- 

 brown longitudinal stripes, about as wide as their intervals, nearly 

 straight, but bent a little below the sutures and at the positions of three 

 girdles of small spots or lunate and more or less confluent dilations of 

 the stripes; the stripes becoming irregular and wider spaced and the 

 upper (now median) band stronger, on the spire. Apex with ter- 

 minal dark dot, obtuse. Whorls 6, moderately convex, the last oval. 

 Aperture ovate, oblique, light flesh-tinted inside, and faintly showing 



OF THE 



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