oy* 
* Say on Shells, &c. 383 
The task presumes the knowledge, not only of fossils in all 
their different states, from the apparently unchanged specimen, 
. to the fragment or section of a cast uninsulably imbedded in its 
rocky matrix, but it also requires an adequate acquaintance with 
recent specimens, or those of which the inhabitants are not 
yet struck from the list of animated beings, in other words 
those of the present, as well as those of the former world. 
Due advantage being taken of the many opportunities which 
are from time to time offered to us, of obtaining knowledge in 
this department, will probably be the means of producing a list 
of American animal reliquiz, coextensive with that of Europe 
at the present day. Inthe present state of the science, how- 
ever, the correct naturalist will fell ita duty which he owes 
to his collaborators to proceed with the utmost caution, that he 
may not add unnecessarily to the already numerous species. 
Genus Alveolites, Lam. 
Coral lapideous, covering extraneous bodies, or in asimple 
mass formed of concentric strata; strata composed each of a 
union of numerous alveoles, which are very short, contiguous, 
reticulate, and generally parallel. we 
Species. 
A. glomeratus., alveoles vertical, subequal, oval, or obsoletely 
hexagonal, much shorter than the diameter, parallel; paries 
simple; strata numerous, forming a rounded mass. (Cabinet 
of the Academy of Natural Sciences.) 
Found often on the coast of North America, cast up by the 
waves, the animals sometimes still living. Forms masses of 
various sizes and figures, generally more or less rounded or 
lobed, and composed of a great number of concentric layers. 
The number of these strata seems to be regulated in some de- 
gree by the quantity of surface they have to cover. Thus if 
the nucleus happens to be a small shell, such as the Natice 
Nasse, &c. of our coast, or even the oyster, (O- Virginica,) 
clam, (V. mercenaria,) &c. the strata are often very numerous ; 
