1894. PROCEEDINGS OF THE NATIONAL MUSEUM. 159 



Mr. Fisher foiiiul this species common on tlie shores of Santa Maria 

 Bay, which is a small bay indenting an island of the same name out- 

 side of Magdalena Bay. The ample quantity he collected includes 

 numerous solid shells of a pure opaque white with a somewhat glazed 

 surface; others spotted here and there with sienna yellow and brown. 

 Many examples are striped and ornamented with more or less conspic- 

 uous bands broken into squarish spots of the same color. Columella 

 generally showing a single blunt tubercle, sometimes not. 



From the U. S. Fish Commission, collected by the Albatross luitural- 

 ists, a magnificent series has been received from Margarita Island 

 (No. 10248, IT. S. N. M). These are of exceeding interest as related to 

 the examples collected by Mr. Fisher, as the two lots illustrate how very 

 considerable is the variation in color, size, and elevation within a 

 comparatively limited area. The Albatross shells are, as a whole, much 

 the largest that I have seen of this species. 



HELIX (ARIOXTA) AKEOLATA, Forbes. 



Var. = Veaichli, Nf;\vcoMi'.. 



Numerous examples. 



Helix Yeatchii (No. 58504, U. S. N. M.), a form generally regarded as a 

 variety of //. areolata., occurs on Cerros Island. It was a specimen of 

 this that furnished an interesting illustration of the extraordinary 

 vitality of these insignificant animals. Dr. Yeatch collected numerous 

 specimens on the island in 1859, and gave some of them to Thomas 

 Bridges. These ultimately passed into my hands. Oneday, upon exam- 

 ining them, 1 noticed that one was alive. I placed it in a box of moist 

 earth, and in a short time it commenced crawling about, apparently as 

 well as ever. After a fortnight's furlough from its long imprisonment 

 in a small box, I put it back again. It had lived six years with(mtfood.* 

 The famous British Museum example of Helix desertoruin lived nearly 

 four years. This last species is from a region in which the physical char- 

 acteristics are in many respects like those of Cerros Island and Lower 

 California. 



expect to find a wide range of modification witliin a territory so peculiar, practically 

 along and narrow belt extending through some 1,000 or 1,200 miles of latitude, 

 from a region of ample, not to say excessive, moisture or humidity to one of extreme 

 aridity, to say nothing of other diverse characteristics which play their part in 

 influencing or inducing variation. 



Whatever may he the value of the characters of the soft parts in the land snails 

 as a basis for grouping or generic segregation, Binney has found in Tryoni, which 

 he has placed in Eupariipha. certain characters in common with Arionta (Steariisiana), 

 in others it is different. Whether this difference is of greater than specific weight 

 or anything more than varietal, remains to be investigated, for it is yet to be proved 

 whetljer the soft parts are out and out, less variable or more constant in their char- 

 acters than the hard parts, that is to say, the external inclosing shell. 



* Proc. California Acad. Nat. Sciences, March 4, 1867. 



