THE NAUTILUS. 5 



A SECOND CONTBIBUTION TO WEST COAST C0NCH0L0GY— I. 



BT HENRY HEMPHILL. 



This may be considered a continuation of the article published in 

 the three closing numbers of Vol. XIV (1901) of the Nautilus, 

 entitled, " A Contribution to "West Coast Conchology." 



Since the publication of that article I have devoted the greater 

 part of three years or more to further exploration of the islands off 

 the coast of southern California, and a large part of a narrow strip 

 of the mainland directly along the coast opposite to the islands, ex- 

 tending from San Pedro, at the south, to San Simeon Point, at the 

 north, the latter point being about one hundred miles, more or less, 

 north of San Miguel Island, the most northerly island of the group. 



The new material secured during this exploration is so variable in 

 every respect and yet so closely connected by intermediate forms, 

 and adds so much to our knowledge, not only of the land shells of 

 this region, but to the subject of variation generally, that I offer the 

 following notes and descriptions for the consideration of those inter- 

 ested in the study of our land shells. 



These islands and the narrow strip of the mainland referred to 

 above constitute a very small portion of a large zoological province 

 that has its southern line at San Diego, and its northern limits at 

 Juan de Fuca Strait, and which may be or is known as the Cali- 

 fornian Province, as most of the forms of molluscan life found within 

 these limits have their metropolis, I believe, within the borders of 

 the State of California. These limits, however, like all other at- 

 tempts to define boundaries in nature, are more or less arbitrarily 

 drawn, and serve only in a general way for the purposes of study, as 

 dividing lines. Quite a number of genera and species that live in 

 this province pass beyond these limits, while a few from the more 

 northern region and even some circumpolar forms, disguised as 

 species, range across the California Province far down into the more 

 southern regions. 



On account of their isolation or separation from the mainland and 

 peculiar conditions in the environment, both the fauna and flora of 

 the islands possess unusual attractions for those interested in the 

 study of the problems of life. I shall go somewhat into the particu- 

 lars and details of the conditions existing on these islands as I have 



