134 THE NAUTILUS. 



sevenths the length of the shell ; outer lip evenly arcuate ; columella 

 very concave, truncate as usual below. Parietal wall covered with 

 a very thin wash of callus, which swells broadly out upon the whorl 

 in the middle, and is abruptly retracted above. Length 68.5, diam. 

 26 mm.; length of aperture 38, greatest width 15.5 mm. 



Santa Marta Mts. at Valparaiso, in forest at 4500 ft. elevation. 



A charming species, remarkable for its acuminate spire, fusiform 

 contour and thin texture. It differs from G. striata by its sculpture 

 and the absence of distinct dark varices. G. plicalula is a smoother, 

 more obese shell, with shorter aperture. No other South American 

 species is nearly related. 



Circinaria ponsonbyi n. sp. Plate vii, tigs. 1, 2, 3. 



Shell much depressed, flat above, broadly and openly umbilicate, 

 thin, slightly greenish yellow-corneous, with a few faint darker 

 streaks ; subtransparent. Surface glossy, irregularly sculptured with 

 wrinkles of growth. Spire almost perfectly flat, the inner whorls 

 hardly perceptibly raised. Whorls a trifle over 5, convex, separated 

 by a deeply impressed, narrowly margined suture, the last whorl 

 wide, evenly rounded at the periphery, convex beneath. Umbilicus 

 about one-fourth the shell's diameter, regularly narrowing, all the 

 whorls being plainly visible. Aperture somewhat oblique, lunate- 

 oval. Peristome simple and thin, the upper termination inserted 

 far above the periphery of the preceding whorl. Alt. 4.9, diam. 

 13 mm. 



Santa Marta Mts. at Cacaguelito, 1500 ft. elevation, under dead 

 leaves. 



It is named for our valued friend and correspondent John Pon- 

 sonby, of London. 



A paler and slightly less depressed form, which may be called 

 C. ponsonbyi clara, was taken at El Libano, at 6000 ft. elevation. 

 It is pellucid, faintly greenish-corneous the largest specimen 

 measuring, alt. 5, diam. 12 mm., whorls 4^. The whorls are some- 

 what more convex beneath, and the apex is larger. 



Aperostoma sanctaimarthce n. sp. Plate vii, figs. 9, 10. 



Shell openly umbilicate, depressed, rich chestnut colored with 

 some yellowish streaks and darker lines at irregular intervals ; 

 moderately solid. Surface glossy, sculptured throughout with close, 

 fine, rib-stria3, which are distinctly wavy or crimped, and occasion- 



