1869. ] HUXLEY—TRIASSIC DINOSAURIA. 39 
gigantic Saurian, which, in virtue of the mass and hollowness of 
its limb-bones, is allied to Zguanodon and to Megalosaurus, and will 
belong to the second division of my Saurian system. None of its 
allies has hitherto been found so deep in the European continent, 
nor from rocks of so great age. These remains belong to a new 
genus, which I term Plateosaurus; the species is Pl. Engelhardtie. 
I shall hereafter publish a full account of the fossils.” 
The fuller account which Von Meyer proniises is contained in 
that splendid menument of paleontological genius and industry, the 
‘Saurier des Muschelkalkes,’ which came out between 1847 and 
1855. The remains enumerated consist of a few imperfect frag- 
ments of a cranium without jaws or teeth, six more or less frag- 
mentary separate vertebre, an imperfect sacrum (consisting of, at 
fewest, three ankylosed vertebree), fragments of ribs, and several limb- 
bones. The centra of the vertebre are nearly four inches long, and 
the most perfect limb-bone is about sixteen inches long. 
This bone is represented in tab. 69. figs. 1-3 of the work cited. 
Von Meyer appears to be inclined to consider it a tibia, comparing 
the smaller end of the bone to the distal end of the tibia of Poi- 
kilopleuron; and the figures support the determination. The other 
figures on the same plate (4, 5) represent the distal end of a femur, 
the posterior face of the outer condyle of which exhibits the remains 
of the ridge which plays between the tibia and the fibula, and is so 
characteristic of the Dinosauria among reptiles. 
In the summary of results at the end of the ‘Saurier des Muschel- 
kalkes,’ the following paragraph occurs (p. 162) :— 
“As to the family of the Pachypoda, with their colossal massive 
forms, it is certain that it is to be met with in the Upper Keuper, 
where it is represented by the two genera Beledon and Plateosau- 
rus, each having one species, B. Plieningert and P. Engelhardt. 
These are different from the Pachypoda of the Oolite and the Chalk.” 
And further on, at p. 163 :— 
“ Concerning the other Saurians, with flat, cutting teeth, which 
are comprehended under Cladyodon, Thecodontosaurus, Paleosaurus, 
and Zanclodon; it has not yet been made out to what family they 
belong, nor whether they are allied to the Pachypoda or not. They 
appear in rocks which occupy the horizon of the lower ‘Grenzbreccia,’ 
and therefore appear to represent a Muschelkalk which is passing 
into the ‘ Lettenkohl ;’ they occur besides in the actual Lettenkohl 
and in the Keuper. The North-American genera Olepsysaurus and 
Bathygnathus appear to be allied forms.” 
It will be observed that Von Meyer here reckons Belodon among 
the Pachypoda. The study of the more complete remains of Belodon, 
described in the ‘Reptilien aus dem Stubensandstein des oberen 
Keupers ’ (Paleontographica, Bd. vii. 1861), however, led to a differ- 
ent conclusion, which is thus expressed (/.¢. p. 346) :—“ Hence 
Belodon was no Pachypode ; if Plieninger has declared it to be such, 
it is because he has mixed up the remains of two totally different 
animals. Belodon was plainly more of a crocodile than of a lizard.” 
The researches of Prof, Plieninger referred to by Yon Meyer are 
