Lull, The Armored Dinosaur Stegosaurus ungtdatus etc. 57 7 



physis which is remarkable not only for its size but also for its 

 peculiar shape. The sense of smell was apparently well developed 

 as was that of sight. Of the auditory sense I am not yet prepared 

 to speak. 



Passing backward along the neural canal one finds two en- 

 largements, one at the fore limbs, the brachial enlargement, and 

 the other within the sacrum. In the former for a Space of about 

 four vertebrae the neural canal after an average width of 2,5 cm. 

 increases to 3,8 cm. and a proportionate height in the eleventh 

 vertebra. 



The neural canal in the sacrum is of startling dimensions 

 having a maximum enlargement of 11,4 cm. and a greatest width 

 of 9,5 cm. and displacing nearly 1200 c. cm. of water, which would 

 give it a mass more than twenty times that of the brain. 



The brachial enlargement was the seat of the Innervation of 

 the powerful fore limbs while that of the sacrum was mainly 

 the reflex and co-ordinating center for the control of the mighty 

 muscles of the hind limbs but more especially the powerful, ac- 

 tive and aggressive tail which constituted the principal means 

 of defense. 



V. Restoration in the flesh. 



Under the direction of Mr. F. A. Lucas, Curator in Chief 

 of the Museum of the Brooklyn Academy of Arts and Sciences 

 and formerly of the U. S. National Museum, two restorations 

 were made by the artist Charles R. K n i g h t. Of these the 

 first was a drawing published by Lucas in 190 1 in his book 

 "Animals of the Past", and again in the Smithsonian Report 

 for 1901, Plate IV. The second restoration is a .Statuette one- 

 tenth linear dimensions. In the drawing, the plates along the 

 back were placed opposite to each other in pairs and the tail 

 bore four pairs of spines whereas in the later model the plates 

 alternated and the pairs of spines were reduced to two; the ap- 

 parent evidence for the alternation of the plates being offered 

 by a specimen in Washington in which they are preserved in the 

 rock in the alternating position and in the fact that those of the 

 opposite sides differ materially in shape and size. This Lucas 

 still thinks conclusive in spite of the fact that no known reptile 

 has alternating dermal scutes, and that the probabilities are that 

 the one row of the plates as preserved in the matrix have shifted 

 forward or backward during maceration or in the subsequent 

 movement of the rocks, as an oblique crushing of fossil bones is 

 a very familiär phenomenon. The disparity in size and shape of 

 the two plates of a pair is not surprising when one considers that 

 the entire hypertrophy of the plate is in a sense abnormal and 

 is comparable to the growth of the antlers of deer of which those 



