356 
THE GEOLOGIST 
Belemnitcs, Glossopctra (sharks' tocth), and the thtinder-atoncs as 
derived from the Piiiua or some other marine shell. Passing by 
Michel Mercati, Boulin, Imperato (who regarded them as stalactites), 
Schwenkfeldt, Libavius, Boetius de Boot, Cerato, Chiocco, Aldro- 
vaudi, Merret, Charleton, and others, who speculated to little 
purpose, copied from each other, or blundered, as Olans Worm 
did, in mistaking them for flints from the chalk, we come to 
Lachmund, who, in 1669, made a further step towards knowledge 
by a primitive distinction of species, giving a goodly number of 
woodcuts, which, though laide in execution compared with our 
modem skilfuhiess in that department of art, are sufficiently indica- 
tive of the objects. 
Our countryman. Lister, though generally so advanced beyond his 
contemporaries in natural history knowledge, did nothing for the 
Belemnites. In 1678, we find him placing them immediately after 
the Echini, or sea-ui'chins, in his division of Lapides turbinati non 
spirati without remark. 
Grew, Jean Schroeder, Sibbald, Leibnitz, and Jacoba3us follow with 
equally bald results up to the time of Lhwyd, who made a great 
collection of minerals and fossils from ditferent countries, particu- 
larly from England, and in 1699 devoted a chapter to Belemnites, 
figuring all the varieties in his possession. While regarding the 
alveolus as the matter which had filled the cavities, he searches Httle 
after the origin of these fossils, and contents liimself with consi- 
dering them as concretions made in the tubes of worms. 
With the dawn of the eighteenth century a more intelligent 
ray of knowledge began to beam, although absurd notions still con- 
tinued to be propagated. Tournefort (1702) persisted in regarding 
them as mere minerals (lyncurium) to favour his doctrine of the 
growth of stones, and their reproduction from germs. Ghedini, 
believing them to be crystals, thought they oiight when perfect to 
have two points instead of one. Helwing, following Lhwyd, looked 
upon them as either marine plants, stony zoophytes, or marine tubes, 
and imagined that they were pointed at both ends before they were 
petrified and formed part of the rock. Volkman (in 1720), speak- 
ing of those of Silesia, supposes them to be spines of fish ; and even 
Swedenborg, having only seen the alveoles, regarded them as the 
