THE NAUTILUS. 69 



distributed, extending from north of Santa Rosa, south on both sides 



' O 



of San Francisco bay to Monterey on the coast, and San Benito Co. 

 in the interior. 



In a shell of so large a distribution it stands to reason that there 

 will be variation, caused by lack of lime for shell-making in some 

 cases, and in other cases to lack of moisture. It has been my ex- 

 perience that the shells collected in wet places were larger, with a 

 more open umbilicus, than those from the more arid regions. 



That nickiiniana Lea is a variety of calif orniensis Lea I can find 

 no proof. The young of californiensis are high-spired with closed 

 umbilicus, the shells do not show the reticulated surface to any ex- 

 tent, and it is strictly a maritime species ; while the young of nickiin- 

 iana are planulate with an open umbilicus, the shells always show 

 the reticulated surface, and it inhabits the moister spots in the 

 wooded zone. 



That nickiiniana and ramentosa are identical no one can doubt 

 who has studied and collected them. I have in my collection a set 

 of twenty nickiiniana from a small canyon in the foothills back of 

 Palo Alto, from which it is possible to select as many different forms, 

 running from a high spire with the lip almost entirely reflected over 

 the umbilicus to low spire with a widely-open umbilicus. The reticu- 

 lated surface and the purplish color of the nacre inside the aperture 

 are present in all of the forms of nickiiniana. In some localities the 

 color band is obsolete. 



E. nickiiniana might be called the typical mollusk of the Upper 

 Sonoran fauna belt in the central portion of the Coast Range system. 



EPIP. CALIFORNIENSIS, Var. ANACHORETA W. G. B. 



This was a deformed nickiiniana, and was so recognized by Mr. 

 Binney 1 in later writings. 



EPIP. CALIFORNIENSIS, Var. RAMENTOSA Gld. 



A small form of nickiiniana from Bolinas, which does not differ 

 from nickiiniana except in size. I have a set from the same 

 locality, which run from large to small, with both open and closed 

 umbilicus. 



EPIP. CALIFORNIENSIS, Var. BRIDGESI NeWC. 



Described from a solitary dead shell from San Pablo, in which 

 'Bull. 28, U. S. N. M., p. 132, 1885. 



