262 Marine Shells of Massachusetts. 
(cit. Hook.), Bceomyces gracilis, Ach. Meth. Lichen 
gracilis, L. White mountains; lower summits. I have 
eighteen species of this genus, all of which were found 
in New England. It is probable, we have the common 
forms of Europe ; and if so, but a small part of our - 
cies have been ascertained. 
In concluding this paper, I am bound to ask of chow 
‘whose learning enables them to see its real value, the 
consideration due, one who has had little experience in 
his subject, and none in illustrating it. To the advan- 
tages of the University Library, containing in Scherer’s 
work alone a certain guide to the greater part of our 
species, and to the kind counsel: of the distinguished 
naturalist who fills the librarian's chair, I owe all the 
assurance I have ventured to shew, and certainly what- 
ever credit that assurance may prove to deserve. 
ART. XL—OBSERVATIONS ON SOME SPECIES OF THE 
MARINE SHELLS OF MASSACHUSETTS, WITH DE- 
SCRIPTIONS OF FIVE NEW SPECIES. By C. B. Apams, 
M.; Prof. of Chem. and Nat. Hist. in Middlebury € 
Vt.; member of the Bost. Soc. Nat. History. nn 
Sept. 1838. 
Ix the infancy of Natural Sina, accurate descrip- 
tions justly claim the chief attention of the lovers of 
nature, Observations on the habits and internal econ- 
omy are of little use unless referred to some well de- 
fined species. Hence the labors of some of the. earli- 
est naturalists are of much less value than would have 
attached to them, had they been more exact in their 
