538 PATAGONIAN EXPEDITIONS: ZOOLOGY. 



granular appearance, more or less developed in different examples. The 

 columella is flat, vertical, nearly straight, with a small, compressed and 

 acute fold above. PI. XLIII0, figs. 6, 6a, represent an"old shell deeply 

 eroded in places. Length 18 (spire largely eroded), diam. n, length of 

 aperture 13 mm. In this lot the cuticle persists over most of the surface. 



At 30 miles above the Sierra Oveja similar large shells were found in a 

 spring. In even the largest, the color-pattern and sculpture persist to 

 the lip-edge. PI. XLIIIa, fig. 7, represents an area immediately below the 

 termination of the suture. The shell measures, length 20.7, diam. 11, 

 length of aperture 13.4 mm. The apex is eroded. 



In a small running stream on the south side of the Rio Chico, 25 miles 

 above Sierra Oveja, two forms of Chilina were found : numerous small C. 

 fulgitrata, the largest 10 to 11 mm. long, and probably not fully adult; 

 and three examples of a very elongate form, one of them figured in PI. 

 XLIV, fig. 23. In this shell the waved streaks appear only on the last 

 half of the last whorl, being preceded by two bands of small spots. * The 

 columella is Lymnseid. Sculpture as in the large decussate C. fulgitrata. 

 Axis rimate. Length 17, diam. 8, length of aperture 10 mm. The sig- 

 nificance of these examples is doubtful. 



Small specimens which seem to be C. fulgurata were taken in a spring 

 on the south side of the Rio Chico, seven miles above the Sierra Ventana. 



i 



CHILINA FULGURATA OLIGOPTYX subsp. nov. 



(Plate XLIV, Figs. 18, i8a, 20-220.) 



The shell is oval, inflated, with short but acuminate spire of between 

 5 and 6 whorls. The cuticle is extremely thin and deciduous, but more 

 or less usually remains on the face and behind the outer lip. It is corneous, 

 or slightly yellowish (somewhat too yellow in figs. 20, 21, 22), with faint 

 reddish-brown streaks. Where the epidermis is removed, the shell is ash 

 colored, or livid purplish or fleshy, sometimes showing traces of the waved 

 color-markings, the spire often dark purple (as in fig. 2,20]. The colu- 

 mella is only moderately arched, and either has no fold (fig. 18) or a 

 small fold may be seen above, in an oblique view, sometimes somewhat 

 stronger than in fig. 22. The outer lip is somewhat thickened within, 

 in adult shells. 



1 The scattered dots shown in fig. 23 are ferrous deposits, foreign to the shell. 



