504 0. C. Marsh—New Jurassic Reptiles. 
A detailed description of these remains will be given in a 
subsequent communication. They are from the Atlantosaurus 
beds of Wyoming. The animal was probably seventy or 
eighty feet in length. 
Stegosaurus ungulatus, sp. nov. 
without a third trochanter, and the ridge between the tibia 
and fibula is only faintly indicated. The tibia is of moderate 
length, and the astragalus is firmly codssified with it. The 
fibula is slender, and united firmly with the calcaneum and 
lower end of the tibia. The present species may prove to be 
generically distinct from the type species, Stegosaurus armatus, 
described by the writer from a different locality. 
In one specimen of the present species, some of the more 
important dimensions are as follows: 
Transverse diameter of occipital condyle -.--. --- an 
Nergeal dumeter.. 3. nec use 25° 
Transverse diameter of foramen magnum . __._. 4-+< 31° 
Greatest transverse diameter of brain cavity...--. 33° 
Length of third cervical vertebra..____.....-.--- 85° 
ewligeh of nhmerds 2.0 590° 
Length of tibia with astragalus ._...._......--.- 750° 
Length of terminal phalanx___.___._._..._.-_--- 85° 
RpvOmtee WAN a Se 
ak, Celurus fragilis, gen. et sp. nov. : 
_, A-very small reptile, apparently a Dinosaur, left its remains 
In the same | i , . 
