LOWER CALIFORNIAN MOLLUSC A. I3I 



The heights of camps given are not generally within 

 several hundred feet of the summits, but are at the local- 

 ities where shells were found living in most cases, while 

 lower down there were more dead ones. As in this State, 

 the occurrence of great numbers of shells on the surface, 

 mostly dead, indicated that the annual production of young 

 is quite limited, but that the shells have been accumulating 

 for many years, while for many miles between such spots 

 not one can be found. The whole collection was made 

 within fort}^ miles north of Cape St. Lucas, and some of 

 the rarest of those distributed so sparinglv by Xantus 

 were found abundant only ten miles north of the Cape 

 and a little over 2,000 feet above the sea. (Distances in 

 straight lines.) 



The following localities of camps were the most pro- 

 ductive of land shells : 



1. San Jose del Cabo and along the little permanent 

 river for twenty miles northward to Santa Anita at a 

 height of 300 feet, and near thirty miles N. N. E. of the 

 Cape. (This place was before estimated at only 100 feet 

 elevation.) 



2. Sierra El Chinche, "Chinchbug Mountains," eight 

 miles north of Cape (about latitude 23°), 2,000 feet alti- 

 tude. 



3. Sauzito, a few miles north and 3,200 feet high. 



4. Sierra El Taste, *' Meadow Mountains," eighteen 

 miles north and 4,200 feet high, 



5. Saltito, north of last and 3,200 feet high. 



6. La Chuparosa (the Humming-bird) is a camp on 

 the Sierra Laguna, and is near 6,000 feet altitude instead 

 of 2,000, as before printed. 



7. Sierra Laguna, about forty miles north, near the 

 Tropic of Cancer, and put down by the U. S. Coast Sur- 

 vey map as 5,924 feet, though Dr. Eisen's barometer 



