63 



shell itself is like aNautilus unrolled ; it has similar chambers, 

 and similar partitions, and the different genera include shells 

 of every degree of curve, between the involute shell of the 

 Nautilus and the straight shell of the Orthoceras, the same 

 variety occurs in the class of shells, chambered like the 

 Ammonite, and include something like fourteen hundred 

 species, every one of which are fossil, and now extinct, except 

 the Nautilus ; and, strange to say, the Nautilus was among 

 the very first of the relatives of the Ammonite that appeared 

 in the world, and has outlived the vicissitudes of time that 

 caused the extinction of hundreds of its relatives, and now 

 lives in the sea, as it did before our white limestone was formed, 

 or before the Lias was deposited, or even before our coal beds 

 were laid down. What a struggle for existence it must have 

 been ! All the genera just mentioned possessed an external 

 shell, but the Ammonite had relatives that had no shell, 

 although they belonged to the so-called shellfish group. The 

 cuttle-fishes, for example, ancient and modern, are relatives of 

 the Ammonite, and they all belong to the " Cephalopoda," or 

 "head-footed" section; because they have their organs of 

 locomotion situated about their heads. Many cuttlefishes live 

 in the present seas, they are captured in the trawls of Car- 

 rickfergus, and in the fishermen's nets of Groomsport ; but 

 what are thus taken in Belfast harbour are diminutive in 

 comparison with the monsters reported to have been met 

 with particularly in the Northern seas, where it is said they 

 were powerful enough to grasp a boat in their arms and drag 

 it to the bottom. Although these creatures have no shell, 

 they protect themselves by a certain inky fluid, which they 

 pour forth in the face of their pursuers, and under cover of the 

 cloud thus made in the water, they make their escape. The 

 great bulk of the shell-less Cephalopoda are recent or living 

 forms, but certain families are found fossil, and they are gene- 

 rally represented in the rocks by the internal shell or bone they 

 possess. The- Belemnite, so very common in the rocks of 



