Parr Ill, Sxcr.i.§1.] ‘TRIASSIC. | 763 
the development of cephalopods in the respective regions. In the 
former area the nautili are represented chiefly by a few species of 
Nautilus (N. bidorsatus, Fig. 361), and the ammonites by species of 
Ceratites (C. nodosus, Fig. 361, C. semipartitus). In the Alpine lime- 
stones, however, there occurs a profusion of cephalopod forms, among 
which a remarkable commingling of Palaeozoic and Mesozoic types 
is noticeable. The genus Orthoceras, so typical of the Paleozoic 
rocks, has never yet been met with in the German Triassic areas ; but 
it appears in the Alpine Trias in species which do not differ much 
from those of the older formatiors. Side by side with these survivals 
of Paleozoic time we find numerous representatives of the 
distinctively Mesozoic tribe of Ammonites, of which characteristic 
species are A. (Arcestes) Studeri, A. (Arcestes) multilobatus, A. 
(Arcestes) neortus, A. (Trachyceras) Aon, A. (Trachyceras) Muensteri,- 
A. (Pinacoceras) _ Metternichit, A. (Phylloceras) Jarbas, Ceratites 
(several species, but without C. nodosus). The fishes of the Triassic 
period have been but sparingly preserved; among the remains 
at present known are species of the genera Gyrolepis, Pholido~ 
phorus, Hybodus, Acrodus, &c. The ancient order of Labyrinthodonts 
still flourished ; numerous prints of their feet have been observed on 
surfaces of sandstone beds, and the bones of some of them have 
been found (Trematosaurus, Mastodonsawrus). Bones and some- 
times even nearly entire skeletons of several lacertilian reptiles 
have also been discovered, the most important genera being Telerpeton, 
Hyperodapedon, and Rhynchosaurus. The earliest demosaurs yet 
known occur in this system (T’hecodontosaurus, Teratosaurus, Palzo- 
saurus, Cladyodon, &c.)."_ They appear to have walked mainly 
on their hind legs, the prints of their hind feet occurring in great 
abundance among the red sandstones of Connecticut. Many of 
them had three bird-like toes and left foot-prints quite like those 
of birds. Others had four or even five toes, and attained an 
enormous size, for a single foot-print sometimes measures twenty 
inches in length. The earliest forms of crocodiles likewise occur 
among Triassic rocks in the genera Stagonolepis and Belodon. It 
has been supposed that evidence of the existence of ‘Triassic 
birds is furnished by the three-toed foot-prints just referred 
to. But probably these are mostly if not entirely the tracks of 
deinosaurs, the absence of two pairs of prints in each track being ac- 
counted for by the bird-like habit of the animals in the use of their 
hind feet in walking. One of the most noteworthy facts in the 
paleontology of the Trias is the occurrence in this system of the 
first relics of mammalian life. These consist of detached teeth and 
lower jaw-bones, referred to small marsupial animals allied to the 
Myrmecobius, or Banded Ant-eater of New South Wales. The 
Kuropean genus is Microlestes (Hypsiprimnopsis). In the Trias of 
North Carolina an allied form has been described under the name 
of Dromathervwm. 
1 See on deinosaurs of the Trias, Huxley, Q. J. Geol. Soc. xxvi. 32. 
