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IX. Researches on the Structure, Organization, and Classification of the Fossil 
Reptilia.* —I. On Protorosaurus Speneri (von Meyer). 
By H. G. Seeley, F.R.S., Professor of Geography in King's College, London. 
Received and Read, February 3, 1887, 
[Plates 14-16.] 
Protorosaurus Speneri, one of the earliest known fossil reptiles, has been already 
studied and. described by Baron Cuvier, Hermann von Meyer, Sir Bichard Owen, 
and Professor Huxley. Occurring in the Kupferschiefer, and therefore of Primary 
age, the exact determination of its structure and affinities has become of some interest 
in relation to the great development of Reptilian life which characterises the succeeding 
Triassic period. 
The most interesting example of Protorosaurus is that originally obtained by 
Spener, which he described and figured in 1710, and regarded as the remains of a 
Crocodile, t His view was confirmed by Link. But Kundmann of Breslau in 1737 
interpreted the remains as those of a new type of large-headed fossil-lizard. This 
conclusion was substantially adopted by Cuvier, who in 1808 made the animal 
universally known as the fossil Monitor of Thuringia.^ Cuvier had never seen a 
specimen ; and was dependent upon the figures published by Spener, Link, and 
Swedenborg, and a drawing, which he published, of a specimen preserved in the 
Boyal Museum at Berlin. He remarks that the head is not without resemblance to 
that of the Nilotic Crocodile, and, as Spener only knew drawings of the exterior of 
* Some time ago the Royal Society did me the honour to place at my disposal grants from the 
Government Grant Fund, for the investigation of the Fossil Reptilia. They enabled me to make studies 
and preliminary descriptions of a large mass of materials in Continental and English collections. Some 
of these, which were chiefly of geological interest, were laid before the Geological Society. Others 
needed further work before they could be used to elucidate the structure, organization, and classification 
of the Fossil Reptilia. The general results to which the researches have led are necessarily connected 
with the detailed evidence on which they rest; and I now propose to submit to the Roal Society any 
account of such genera and ordinal groups as fall within this field of work, as well as discussions of 
the distinctive osteological organization which some orders have in common, before summarising the 
classification. 
t ‘Miscellanea Berolinensia,’ Berolini, 1710, T. 1, p. 99. “ Disquisitio de Crocodilo in Lapide, &c.,” 
figs. 24, 25. 
+ ‘ Annales du Museum,’ T. 12, p. 79, Plate 10. 
2 B 2 
17.9.87 
