104 
The small light-coloured, calcareous, spongite, or alcyonite, Plate 
IX. Fig. 14, possessing somewhat of a conical form and a rugose sur- 
face, and exhibiting, when examined with a lens, evident marks of an 
original spongeous substance, was obtained, by Mr. Strange, from Swit- 
zerland. A specimen, approaching exceedingly near in size and form 
to the one here figured, was suspended in water slightly acidulated 
with muriatic acid. As the acid acted on the carbonate of lime, the 
membraneous part of the sponge began to appear; and being libe- 
rated, extended itself beyond the remaining solid mass, in tolerably 
coherent flexible flocculae. When it had been submitted so long to 
the action of the acid, that the carbonate of lime was nearly removed, 
a dark brown reticular mass was left, bearing the general form of the 
fossil, and manifesting its original spongeous reticulated texture. So 
coherent was this mass, as even to bear its removal, by pouring into 
another glass, without suffering any material injury to its form. It 
was, however, at last broken, upon pouring additional water into the 
phial which contained it. Another specimen, as similar in its form 
and size as could be found, was then subjected to the action of the 
acid for the purpose of obtaining a correct sketch of the remaining 
membrane, which is given Plate IX. Fig. 15. 
The small calcareous fossils, Plate X. Fig. 7, 8, 9, and 10, are from 
the Canton of Basle, in Switzerland. Their animal origin is rendered 
evident by their alcyonic structure as discovered by the aid of a lens. 
The specimen of a hemispherical form, delineated at Fig. 8, has a 
central stellated opening, which has every appearance of having been 
the residence of a polypous hydra, and which is surrounded by radi- 
ating depressions, such as ■would seem to agree with the arms of the 
animal. On close inspection, it is seen, that the whole substance of 
the alcyonium is closely beset with innumerable minute openings, which, 
in all probability, teemed with these extraordinary animals. 
The natural history of these substances teaches us, that individuals 
of different species are frequently found growing adherent to each 
