ON LAND AND FRESH WATER MOLLUSCA OF 

 LOWER CALIFORNIA. No. 2. 



BY J. G. COOPER. 



Since the publication of article No. i in these Proceed- 

 ings, 2d Series, Vol. iii, April, 1891, p. 99, another 

 expedition, sent out by the Acadeni}^, has made large 

 additions to our knowledge of the mollusca of the penin- 

 sula and gulf, a full account of which will need much 

 time for preparation. As a beginning, I now give addi- 

 tional notes on those terrestrial species that are well 

 known, leaving for future articles the notes and illustra- 

 tions relating to new or undetermined species. 



I may here refer to an article published by me in 

 Zoe, Vol. Ill, p. II, April, 1892, giving a full catalogue 

 of the species then ascertained to inhabit the land and 

 fresh waters between the United States boundary at Fort 

 Yuma, on the Colorado River, to the Pacific and south- 

 ward, of which the following is a summary: 



TERRESTRIAL. FRESH-WATER. 



Number known 32 Number known 12 



Found north of boundiiry 14 Found north of boundary 10 



Found also in Mexico 5 Found also in Mexico 4 



Additions in Zoe list 10 Desert sjjecies 8 



Additions now made 4 Brackish water species 8 



Additions in Zoe list 8 



Additions now made 6 



Total terrestrial and fresh-water species 54 



x\s a correction of that list, I must state that Mr. Hemp- 

 hill informs me that he never found No. 36, ]^eyoiiicella 

 olivacea, on the peninsula, and its occurrence there is very 

 doubtful. 



The present collection was made chiefly by Mr. Gustav 

 Eisen, whose department was the invertebrates, but many 

 were also obtained by Mr. W. E. Bryant, especially marine 



•2d Ser. Vol. IU. ( 16 ) October «, 18'J2. 



