“And how the nuns of Whitby told How of countless snakes, each one Was changed into a coil of stone When holy Hilda prayed, Themselves within their sacred bound, Their stony folds had often found.”—CANTO 2. Richardson, in his Geology, relates the “instance of a dealer who having been requested by his customers to supply them with some of the creatures which had escaped decapitation, contrived to manufacture some heads of plaster of Paris, and affixed them to the specimens; thus he pursued a thriving trade, until some remorseless geologist visiting the place, not only beheaded the reptiles, but showed that they were in reality fossil shells.” With the figure of the ammonite every reader of geological books is familiar; it is, perhaps, the best known and most beautiful of all our fossils. We give below a representation of four different kinds, found in the lias and oolite. [Illustration: 1. AH. BECHEI. LIAS ] [Illustration: 2. AM. BRODIEI. OOLITE. ] [Illustration: 3. AM. HUMPHRIESIANUS. LIAS. ] [Illustration: 4. AM. WALCOTTI. LIAS. ] In general outline it will be seen that the ammonite somewhat resembles the nautilus, and yet there are characteristic differences that are so striking as to mock the development hypothesis. In the first place, the shell of the ammonite, though of the same flat discoidal form as that of the nautilus, appears to have been much thinner; secondly, it will be seen that the whorls of the ammonite are rounder and more in number than those of the nautilus; and lastly, the siphuncle, of which more presently, runs _round_ the chambers of the ammonite, but _through_ the chambers of the nautilus. Let us look a little at each of these peculiarities; and to aid us, we give below two drawings of sections of ammonites, and two drawings of a nautilus. [Illustration: AM. KŒNIGI LIAS. ] [Illustration: NAUTILUS. (FOSSIL.) HORIZONTAL. ] [Illustration: AM. HETEROPHYLLUS. LIAS. ] [Illustration: NAUTILUS (FOSSIL), SHOWING THE SIPHUNCLE. ]