THE NAUTILUS. il 
tion of the shell is also impaired and the limey portion made more 
conspicuous through its general bleaching effect and whitening of 
the callus of the columella. Mr. Tryon’s Physa politissima, col- 
lected by Rey. J. Rowell, at Sacramento, and described and figured 
in Am. Journ. Conch., Vol. I, 1865, is probably one aspect of Lea’s 
P. triticea. It is from a lower station, with an elevation variously 
stated as from thirty-one to eighty-two feet above sea level, and 
within the same drainage system. 
The summing up of the foregoing leads to the conclusion that the 
first-named species (that made by Dr. Lea) is but a dwarfed and 
arrested aspect of P. gyrina, aud Mr. Tryon’s species is but another 
facies of the same. 
Of the number of species that have been made upon characters 
that are simply those of adolescence, it would be interesting to know. 
Doubtless a great many, and not only among the fluviatile and 
lacustrine forms, but among marine forms also. This fact almost 
daily presents itself where one’s routine work is the selection of 
specimens or examples for a great museum, and the determination 
of species from a great mass of material. Sometimes one is led to 
think that it is a pity, either that animals are not born fully grown, 
or that those who describe them do not bear in mind the fact that 
mollusks, etc., like men, have to advance by gradual growth from 
babyhood and the various stages of adolescence to maturity. 
HELIX NEMORALIS IN VIRGINIA. 
BY H. A. PIUSBRY- 
The H. nemoralis does not appear to have been naturalized in 
America except at Burlington, New Jersey, where it was introduced 
by Mr. W. G. Binney, many years ago. A short time since, I 
received a parcel of nemoralis shells from Prof. Jas. H. Morrison, of 
Lexington, Va. In response to a letter of inquiry Prof. Morrison 
gives the circumstances of its introduction as follows : 
“The first specimen was found in the grounds of the Virginia 
Military Institute, in 1886, and was sent to Prof. Baird, who called 
it ‘Helix hortensis,’ stating that this was a new locality. A few 
days afterwards I found quite a number of specimens and sent part 
of them to Mr. Tryon, who said they were ‘ Helix nemoralis’, and 
gave all the necessary information to establish this point. I found 
