128 THE NAUTILUS. 



where interrupted by narrow patclies or streaks of darker ground- 

 color. On the base there are often several spiral corneous bands, 

 leaving;: one to three spiral zones of long white granules. The rib- 

 stria; are nearly as wide as their intervals, weaker in the corneous 

 patches, and continue upon (he base. Whorls rather convex, the 

 upper ones more convex ; last whorl rounded, with a \(My weak spiral 

 cord detining the base, sometimes almost obsolete. Tiie aperture is 

 oblique; peristome well expanded, white, the columellar margin 

 built forward, in a plane with the outer lip. 



Length 12.7, diam. 6.6 mm.; whorls 10. 



Length 11.3, diam. 5 mm.; whorls 9^. 



Length 9, diam. 4.3 mm.; whorls 9. 



Near Sancti Spiritus, Province of Santa Clara, at a place called 

 " San Jos^ rocks,'' about two miles northeast of the city. 



This is a larger shell than M. peiiticmvs (Orb.), also known as 

 M. (unicnia (Pfr.), with stronger, closer striae continuing over the 

 base ; it is not so v/ide and the spire is less attenuated above. The 

 smallest shell found in a large series is 9 mm. long. Nearly all are 

 over 10 mm. 



San Jose rocks, conspicuous from Sancti Spiritus as a white ridge, 

 stand upon a low ridge of gneiss which runs north of Sancti Spiritus. 

 Tiie rocks cover only a small area, but form a labyrinth of fissures, 

 caves, tunnels, deep holes and knife-like crests, the whole clothed 

 with trees and vines. Deeper and deeper I went, getting big Me- 

 galomastomas and Helicea in the cool rock chambers. The charm- 

 ing new Urocopiis cora hung on the cliffs. Operculates quite new 

 to me were turning up. Finally I was quite lost in this absurdly 

 diminutive jungle. I had dropped down several cliffs of eight or 

 ten feet in gaining the heart of the thicket, and there was nothing 

 to do but go on in as straight a course as I could steer. After a 

 hard scramble of half an hour I emerged on the lower side, wet with 

 perspiration and scratched by the sharp rocks, but happy in the pos- 

 session of a fine bag of snails. 



The rocks of San .Jose are apparently a remnant of the Oligocene 

 deposits which must once have heavily blanketed the gneiss in this 

 region. Little trace of these beds remains in the country around 

 Sancti Spiritus. 



I found a variety of this species at Zaza del Medio, where on a 

 small rocky hill or on the adjacent slope to the river I picked up two 



