.21 Lowei' Calif ornian Shells. [zok 



B. Marine Species, i. Pulmonate. 



Melampus olivaceus Carpenter, 1857. Mazatlan, Mexico, to 

 Monterey Bay, California, lat. 23° to 36° 30', salt marshes. 



Onchidella carpenteri W. G. B., i860. Cape St. Lucas, 

 Xmitus. Doubtfully reported from lat. 48° north. 



Pedipes liratus W. G. B., 1861. Cape St. Lucas, Xantus, to 

 San Diego, y; G. C. 



P. UNISULCATUS J. G. Cooper, 1867. San Pedro, California 

 (types). Head of Gulf of California, Palmer. 



Siphonaria ^quilirata Carpenter, 1867. Margarita Island, 

 lat. 24° 20', to South America (Carpenter). 



S. LECANIUM Philippi, 1846. Cape St. Lucas to Acapulco, Mex- 

 ico (Carpenter). 



2. Estuarine. Non-Pulmonate, operculate. 



Neritina californica Reeve, 1845. Gulf of California. 



N. CASSICULUM Sowerby, 1832, is supposed by Carpenter to have 

 been obtained at " San Miguel, lat. 2cf , Lower California," by Lieut. 

 Greene, U. S. N., also Mazatlan, Mexico. 



37. Neritina picta Sowerby, 1832. Panama, Cuming. North 

 to Guaymas, lat. 28°, on gulf coast, and Magdalena Bay, lat. 23 ' 

 30', on west coast of peninsula, in brooks near the sea. This 

 scarcely deserves to rank as a fresh-water shell, as it always occurs 

 near tide-water and must travel through the sea along the coast. 

 The habits of the other two species have not been recorded, but 

 some are known to be entirely marine, others also found in fresh 

 water. 



Mr. Binney also includes among " Land and Fresh-water" shells 

 the Truticaicllas, which are allied to some land genera, but whollv 

 marine, so I omit them here. 



C. Colorado Desert Mollusca. 



Very little is known of the Land and Fresh-water species east of 

 the peninsula mountains and north of lat. 31°, but the region is 

 known to share in the arid and barren characters of the desert north 

 of the boundary with scarcely any fresh water, a minimum of rain, 

 and consequently a barren soil. Prof Blake, Mr. Orcutt and 



