MOLLUSCA. 
229 
species {Batissa ) . A probably incomplete list of 100 species 
of land-shells and thirty-three from freshwater, known from 
other more recent collections, is added, with some general 
remarks on the Mexican fauna and its resemblance partly to that 
of North America, partly to that of the tropical parts of America. 
The southern provinces Chiapa, Tabasco, and Yucatan are ex- 
cluded from this list, as belonging rather to Central America 
proper. Much attention has been paid to some older synonyms 
of Mexican species in the works of Valenciennes, Beck, and 
others. 
Gabb, W. M. Description of three new species of Mexican 
land-shells. Am. Journ. Conch, i. pp. 208 & 209. 
9. North America. 
(Particular faunas.) 
Newcomb, W. Descriptions of nine new species of Helix in- 
habiting, California. Proc. Californ. Aead. Nat. Sc. iii. 
1864, pp. 115-119. 
This paper contains also a list of eighteen other Californian 
species of Helix , contained in the State Collection [one of which 
only, H. chersina (Say), occui’s also in the eastern provinces of 
the United States]. 
. Catalogue of Helices inhabiting the west coast of Ame- 
rica, north of Cape St* Lucas and west of the Rocky Moun- 
tains, together with remarks upon some of the animals and 
their special distribution. Am. Journ. Conch, i. pp. 342- 
350. 
Forty-three species, one admitted to be identical with the 
European Hyalina fuha (Drap.). [Most of them belong to one 
natural group of the genus Helix ^ Arionta (Leach), type H. ar^ 
bustormii ] . The variations of size in the same species are given 
by measurements of the maximum and minimum in seven 
species, p. 350. 
Tryon, G. W. Catalogue of Mollusca collected by Prof. D. 
S. Sheldon at Davenport, Iowa. Am. Journ. Conch, i. 
pp. 68-70. 
One hundred and two species, of which more than one half 
(52) are Unionidm. These latter exhibit frequently warm pink 
or purple nacres and a bright yellow or green polished and 
splendidly rayed epidermis. Melantho subsolida (Anthony) 
attains here to 2 inches in length. Vivipara intertexta (Say) 
has not been reported before from north of Louisiana. Unio 
higginsii and Somatogyra \^Amnicola^ depressa have not been 
discovered elsewhere. 
