FOSSIL FISHES AND CEPHALOPODS. 
77 
Pariasaurus (fig. 52) from the Karoo formation (Trias) of South 
Africa, one of the most remarkable of fossil reptiles, which 
also occurs in Eussia. It belongs to a primitive section of the 
Theromorphs, or Anomodonts, whicli include the ancestors of 
Mammals. 
Fig. 51. — A Giant Pterodactyle {Fteranodon occidentalix) fkom the Cketaceous of 
Kansas. (Original span about 18 feet.) Compare the wing which is supported by the 
outermost finger with that of the Bat drawn in Fig. 7. 
Of the galleries running northwards from the Fossil Eeptile 
Gallery, the one nearest to the Central Hall is entirely devoted 
to the display of the enormous collection of Fossil Fishes. A 
great proportion of the oldest of these belong to groups now 
quite extinct. Perhaps the most remarkable of all, and cer- 
tainly those most unlike existing forms, are the armoured 
Devonian types, described as Cephalaspis, Ptericlitliys (fig. 53), 
&c. In the figure of the latter letters are placed on the various 
plates of armour, as well as on other parts of the body. The 
explanation of these will be found in the " Guide to Fossil 
Fishes." 
The next contains the Cephalopods, a group of molluscs 
abounding in extinct forms, of which the Belemnites, 
Turrilites (fig. 54), and Ammonites (fig. 55) are some of 
the best-known. The form and structure of their nearest 
living representatives, the various species of Cuttle-fishes, Squids, 
Argonauts, and ISTautilus (fig. 30) are illustrated by models and 
drawings and specimens placed near the entrance of the gallery 
and along the top-line of the wall-cases. The third gallery Extinct 
contains the remaining Molluscs and Brachiopods ; the Echino- aart^pianu^^ 
derms, Annelids, and Crustacea ; the fourth, the Corals, Sponges, 
