Maryland Geological Survey 199 



dimensions 



Length 394 mm. 



Width proximal end 116 mm. 



Width mid shaft 60 mm. 



Width distal end 106 mm. 



The tibia (No. 5657, F. S. National Museum) and the fibula (No. 

 5656) (pi. xvii, fig. 3) both resemble those of Morosaurus lentus, except 

 that they are again much less robust and are relatively very much longer 

 in proportion to the length of the femur, though until the actually asso- 

 ciated bones of one animal are found such proportions in Pleurococlus may 

 be open to doubt. 



Length of the tibia 330.0 mm. 



Width of proximal end 112.5 mm. 



Width of distal end 72.5 mm. 



Width of mid shaft 42.5 mm. 



Dimensions of fibula: 



Length 323.0 mm. 



Width proximal end 75.0 mm. 



Width distal end 48.0 mm. 



Width mid shaft 34.5 mm. 



• The tarsus seems to be represented by an astragalus (No. 5452, U. S. 

 National Museum), which is listed as the type astragalus of Allosaurus 

 medius, but does not correspond either to the form of a theropod 

 astragalus or to the dimensions given by Marsh in his original descrip- 

 tion. The bone is an irregular oval, somewhat pointed at one end, al- 

 though, as little of the original surface is preserved, it is difficult to tell 

 how much of the present form is correct. 



Width 93 mm. 



Fore and aft diameter 63 mm. 



Greatest thickness 34 mm. 



The metatarsals are shorter and more robust than the metacarpals so 

 that the foot is short and compact. 



The first metatarsal, that figured, is one of the cotypes (No. 2267, U. S. 



National Museum) . Its dimensions are : 



Length 66 mm. 



Width of proximal end 53 mm. 



Width of distal end 42 mm. 



