PILSBRY: NON-MARINE MOLLUSCA OF PATAGONIA. 535 



minute, indistinct spiral striae. The ground-color is rather bright yellow 

 on the last whorl, copiously marked with purplish-brown zigzag streaks, 

 each with 4 principal angles projecting forward, and more or less 

 widened at the angles. On the latter part of the whorl the streaks dis- 

 appear, leaving four bands of spots. The spire is dark blue, with dusky 

 brown zigzag markings on the penultimate and next earlier whorls, those 

 above being uniform purplish-brown or dull blue. Whorls between 5^ 

 and 6, convex, regularly increasing, the last elliptical, widest in the middle. 

 The aperture is nearly vertical, white, rich brown deep in the throat, 

 showing the external markings as purplish-brown spot-bands. Columella 

 rather broad, white, bearing a rather stout oblique fold above, a slight 

 spirally entering prominence below it (in most examples scarcely showing 

 in front view). Parietal callus thin, bearing a low, spirally entering fold 

 at its lower third, usually hardly visible in a front view. 



Fig. 24. Length 25, diam. 14.2, length of aperture 18 mm. 



" 25. " 25.2 " 14.5 " " 18 " 



" 26. " 23.5 " 13.2 " " 16 " 



24 " 13 " " 16 " 



Mount of Observation, 40 miles south of Santa Cruz River. 



This fine species was collected in some quantity. It is distinguished 

 from Chilina puelcha d'Orb. by the presence of a parietal fold, among 

 other peculiarities. No other species from south of the Rio de La Plata drain- 

 age has this fold developed. In the young stages (figs. 27, 28) the color- 

 streaks are less distinctly defined, fading at their edges, 1 and the parietal 

 fold is present only as a very thin whitish callus- 



CHILINA SMITHI sp. nov. 



(Plate XLIII, Figs. 1-4.) 



The shell is oblong-ovate, solid, minutely rimate, rather rudely sculp- 

 tured, with wrinkles of growth and more or less distinct spiral lines ; always 

 more or less deeply eroded in the adult stage. The color of the cuticle 

 is olive, or in the newly-formed band behind the outer lip it is yellow. In 

 adults a large part of the cuticle is wanting, exposing the calcareous layer 

 beneath, which is blue and gray, or when deeply worn (as in figures 3 and 

 4), it is white. The spire is worn, whorls convex, the last one distinctly 

 shouldered, compressed laterally, widest at the middle or below it. The 



1 They are represented entirely too sharply defined in figures 27 and 28. 



