Rosinus, Waloh, Lemery, and others writing after him followed not in the new path opened ont to them, but reiterated former absurdities.

Bruckmann thinks them a kind of pholas, or boring shell; Bourquet holds to the old notion of their being teeth of whales; Klein even in 1731 regards them as worm-tubes, although three years later he comes round to the opinion that they were nearly allied to the Argonautes; Spirulæ, and chambered shells. Dufay, one of the numerous writers who followed, states that burnt belemnites have the property of being luminous after having been calcined upwards of five years. We have not tried the experiment, and cannot, therefore, speak to the accuracy of the assertion.