i “ea 
tes i 
id peas ° 
- local ere. ies is accus d to grow,—by / 
indi ty where each species is et te ‘ei 7 nh 
T. Bland on the Geographical Distribution of Mollusca. 401 
Professor Adams, in his catalogue of Panama shells, carefully 
adds the stations, and habitat of each species, from the authori- 
tes to which he refers in its synonymy,* as well as from his own 
experience,t and distinguishes original, from other testimony. 
He remarks in the Introduction, “on errors respecting the habitat 
of species,” from which we subjoin extracts,;—we refer our read- 
ers to the work itself for various useful illustrative notes. 
“Those who are familiar with the frequency and magnitude 
of the errors which occur in the works of the most celebrated 
received without sufficient scrutiny. In addition to the errors 
likely to occur in the verbal communication of statements respect- 
ing habitat, naturalists at home are of course subject to all the 
mistakes which. the original collectors have made. ‘These per- 
sons often mix the collections made in various places, and depend 
 0n memory for the localities, although they are often unable to 
distinguish the species when placed side by side. 
Another class of errors, we fear, must be laid to the charge of 
the writers themselves. When we see a marine species affirmed 
to inhabit the Mediterranean, Senegal, the Indian Ccean, New 
Holland, éc., we may often suspect the error to arise more or less 
from erroneous testimony. But when one species is referred to 
two distinct zoological provinces, which are known to contain 
analogous but not identical species, we must sometimes suspect 
the author of confounding such species.” —p. 24. 
- “For all these causes of error there is but one remedy, and 
that is not infallible. Rejecting the testimony of careless and 
Meompetent observers, and all hearsay testimony, we must rely 
%n the testimony of competent observers. We may hope for 
accuracy when they shall remember, that a very few errors may 
essentially change the aspect of the plan of distribution, and pre- 
Vent all correct generalizations.” —p. 25. Ett 
It would be unfair to withhold a statement of the opinion of 
rt. Binney on this branch of our subject. His chapter in the 
Worl: previously mentioned, we refer to vol. 1, chap. in, entitled 
“OF some of the obstacles impeding the study of zoology, aud 
the means of overcoming them,” is unquestionably replete with 
Interest. In his comments, contained in that chapter, on the hy- 
sat 2, ge hells Sebeake apie tates io 
id 5 3 regards synonymy, is worthy of uni- 
val Aaa aaa 1 ane ; jowieal order, and the dates 
says. Lyell, speaki 
shich have been often confounded together, 
rm Which are equally applicable to zoology. —Principles of Geology. 
eication of the country where a plant 
Sa 
