THE NAUTILUS. 101 



periphery of the last whorl some excessively faint spiral lines 

 may be seen under a hand-lens. The first whorl begins with 

 irregular radial ripples, then is very minutely rugose with in- 

 conspicuous rounded papillae, widely spaced, and arranged in 

 forwardly descending, curved series. Whorls 6, rather convex, 

 those of the spire rather narrowly coiled, the last rapidly enlarg- 

 ing, descending somewhat to the aperture. The aperture is 

 large and decidedly oblique. The peristome is thin, the upper 

 and outer margins narrowly expanding, basal margin narrowly 

 reflexed ; the columellar margin runs rather far forward, and is 

 much dilated at the insertion, the external edge straightened. 



Height 15, diam. 22 mm. ; umbilicus 2.6 mm. 



Locality. — Trinidad, on the west coast, near San Borga. 

 Wm. M. Gabb. Type no. 58127 A. N. S. P. 



I have not been able to locate Trinidad on the map. San 

 Borgia is a mission in the interior, below the 29th parallel. 

 There are several other specimens in the collection, all taken by 

 Gabb. 



This is one of several forms which W. M. Gabb determined 

 as Helix carpenteri Newc. — a Califomian species which differs by 

 its " numerous very minute spiral striations". Sonorella iner- 

 rilli Bartsch is more depressed, with a smaller aperture and 

 larger umbilicus. The several species described from the pen- 

 insula by M. Jules Mabille differ in proportions from this one. 



SONOKELLA ULTIMA U. Sp. PI. 2, fig. 5. 



The shell is narrowly umbilicate (the width of the umbilicus 

 contained about twelve times in the diameter of shell); rather 

 thin ; depressed-globose, with very low conic spire ; pale cinna- 

 mon, fading to opaque white on the base, having a chestnut- 

 brown band above the periphery. The surface is glossy, weakly 

 marked with growth-lines, without spiral striation. Whorls 

 4^, moderately convex, those of the spire slowly increasing, the 

 last whorl very wide, deflexed in front. The aperture is large, 

 oblique. Peristome thin at the edge, but having a rather wide 

 low white callous rim within, the terminations strongly converg- 

 ing ; the upper margin is unexpanded, outer and basal margins 

 narrowly expanded ; columellar margin carried forward, straight- 



