204 
PROFESSOR n. G. SEELEY ON THE STRUCTURE, ORGANIZATION, 
the Ju<der fossil from the others, the form of the femur is no less distinctive in its 
prop-like character and massive width. In Protoroscairus Speneri the bone is between 
four and five times as long as wide ; here it is between two and three times as long as 
wide. The dorsal ribs shorten towards the sacrum in a way of which the Vienna 
fossil gives no indication, and which is not paralleled in any of the specimens referred 
to Protorosaurus Speneri or P. Linkii, since the last rib hardly exceeds the length of 
a dorsal vertebra. The ilium is in the form of an arch, the extremities of which rest 
against the bodies of the vertebrae, and to the middle of the outer curve of the arch 
the femur articulates. If all the vertebrae between the extremities of the arch are 
regarded as sacral, the sacrum includes five or six vertebrae at fewest. These 
characters are very scanty evidence of the animal, but they indicate in my judgment 
that the Jugler fossil belongs to a new genus and species. Till the genus is named 
the fossil may be referred to as Protorosaurus Meyeri. There can be no doubt that 
the Dresden fossil belongs to the same genus as the Jugler example, but I cannot 
at present determine whether it is specifically distinct. 
From this discussion it appears that Protorosaurus Speneri as defined by vox Meyer 
included two or three genera and several species; and that the materials available 
for the elucidation of the type of the genus make known, more or less perfectly, 
the parts of the skeleton which are missing from the College of Surgeons specimen. 
The Jugler and Dresden specimens make known a form of pelvis as strong as 
anything met with among Ornithosaurs and fossil Reptiles, and show that the strength 
of the bones in the sacral region is associated with shortness and strength of the femur. 
I now propose to use this evidence, brought together by vox Meyer in the 
discussion of the affinities and structure of the type of Protorosaurus. 
Part IV. 
Comparison of Protorosaurus with other Types of Animals. 
The skull. —Imperfect as is the preservation of the skull, it can be almost completely 
restored. The pterygoid bones, being still connected with the quadrate bones, furnish 
approximately the width of the palate in the transverse line of the quadrate 
articulation as not less than 4'5 centims., nor more than 6 centims. This is more than 
the width of the superior aspect of the back part of the skull as preserved, which 
would not have exceeded 2'5 centims., and if to this the width of the lost post-frontal 
and squamosal bones is added the width of the back of the skull presumably would 
still be less than the measurement over the condyles of the quadrate bones. The 
quadrate bones may have been inclined so as to converge upward, and thus have 
given an obliquely inclined aspect to the sides of the head, making its transverse 
section trapezoidal. If an attempt is made to reconstruct the palate (fig. 1), it is 
manifest that if the narrow internal facets of the pterygoid bones met each other 
