22 Lower Californian Shells. [zon 
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., 1860. Cape St. Lucas, 
Xantus. Doubtfully reported from lat. 48° north. 
PEDIPES LIRATUS W. G. B., 1861. Cape St. Lucas, Xantus, to 
San Diego, 7, G. C. 
P. unisuLcatus J. G. Cooper, 1867. San Pedro, California 
(types). Head of Gulf of California, Palmer. 
SIPHONARIA AQUILIRATA 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-PULMGNATE, OPERCULATE. 
NERITINA CALIFORNICA Reeve, 1845. Gulf of California. 
N. CAssicuLuM Sowerby, 1832, is supposed by Carpenter to have 
been obtained at “ San Miguel, lat. 29°, 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 
searcely 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 Zruncatellas, which are allied to some land genera, but wholly 
marine, so I omit them here. 
C. CoLtorapo DESERT MoLyusca. 
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 
