208 CALIFORNIA ACADEMY OF SCIENCES. 



species, on the islands of the gulf. As they did not usually 

 go in company to the same places, different species were 

 found by various collectors. The Academy is also in- 

 debted to Mr.L. Belding for many good living specimens 

 obtained by him south of La Paz, in the rainy season, 

 and therefore more perfect than usual. 



I am glad to be able now to confirm the occurrence of 

 two of the very rare species first found at Cape St. Lucas 

 by Xantus (de Vesey), which have escaped collectors for 

 thirty years since. The mystery of their scarcity is solved 

 by finding that they belong to the highest regions north 

 of the cape, in the Sierra Laguna, about latitude 23'^ 50', 

 which rise to 5,000 or 6,000 feet; thence they occur with 

 less abundance downward, and especially on the east side, 

 living on the north slope of the hills at various levels, and 

 sometimes washed down, living or dead, to the sea-level. 



Mr. Eisen's observations on the large species were very 

 interesting, as indicating an imperfect distribution in 

 zones, as follows: 



Feet , Feet , 



B. pallidior 100 to 500 B. proteus 2,000 to 3,500 



B. iusceudens 100 to 3,000 B. viir. beUliugi 3,000 to 5,000 



B. sufflatus 2,000 to 3,000 B. iirteraisia 500 to 3,000 



This distribution fully contradicts the theory that the 

 two largest (named in upper fine) could have been intro- 

 duced from South America as food (though several species 

 are sold in the markets of that country), as no evidence 

 of their use in that way was seen. As to introduction 

 with roots, Mr. Eisen thinks that B . proteiis is too numer- 

 ous on the mountains to have been imported, not occurring 

 so plentifully in the more cultivated lower districts. 



BuLiMULUs ARTEMISIA W. G. B. i86i. " Promontory 

 of Cape St. Lucas, latitude 22^ 52', i exa.," Xantus. 

 Two found on Sierra Laguna in the fig region, by Eisen, 

 at 3,000 feet; they have one more whorl (9), and are 



