THE NAUTILUS. 17 



Main Range. Waianae Range. 



Spirizona nigrolabris. Spirizona. 



Spirizona chlorotica. 



Intermedia. 



Porphyrea. Porphyrea. 



Porphyrostoma. Cylindrica. 



Varieyata. 



THE LAND MOLLUSCA OF SAN MATEO POINT, CALIFORNIA. 



BY HARRY EDSON. 



San Mateo Point is a heavily-wooded knoll containing about one 

 and one-half acres of ground, on the San Francisco bay coast mid- 

 way between San Mateo and Burlingame. It is practically an 

 island as far as the land mollusca are concerned, beiag entirely sur- 

 rounded by water and salt marsh with the exception of a wagon road 

 that during the rainy season, the only time the snails travel in Cali- 

 fornia, is covered with water most of the time, so that there has 

 been no very recent addition to the molluscan fauna, which is rather 

 large considering the area of the collecting ground, and that the 

 nearest place any molluscs are found is over three miles away with 

 the town of San Mateo and the salt marsh intervening. 



& 



LIST OF SPECIES. 



Epiphragrnophora arrosa, Gould, found in large numbers on the 

 western or bay side exposure. I was unable to find any on the 

 opposite side. 



This species showed a very great variation, running from a very 

 dark shell with no superior color band to a light-colored shell with 

 dark band, also an albino form some without any band and others 

 banded, one of the latter had a bright orange band. 



Epiphragmophora nickliniana, Lea. This shell was found rather 

 sparingly, buried under the debris in some small water channels 

 running from the center of the point. 



Gircinaria vancouverensis,, Lea, a few specimens found on the 

 west side. 



Gircinaria duranti, Newc., found on a little hill in the center of 

 the point that the Indians had evidently used as a place to hold clam 

 bakes. 



