G. F, Eaton — Characters of Pteranodon, 83 



ing words (this Journal, vol. xxvii, May, 1884) : " an enor- 

 mous sagittal crest extends far backward, and somewhat 

 upward." The accuracy of this statement is denied by Prof. 

 S. W. Williston (Kansas Univ. Quarterly, vol. i, No. 1, July, 

 1892), whose views have been accepted largely because of the 

 fact that he collected the head of Marsh's type of Pteranodon. 

 Material in the Yale Museum now shows that, contrary to 

 Williston's opinion, the elongation of the crest, as figured by 

 Marsh, was too conservative. Reference to Plate VI, figure 1, 

 will show its true form, taken from an actual specimen, which 

 is indicated by the continuous line. Marsh's incomplete 

 restoration is shown by the dotted line, while Williston's 

 figure of the skull, shorn of its crest, is reproduced carefully 

 in figure 2. Prof. Marsh laid emphasis on this character, and 

 it is of great importance that this error be corrected at once. 

 Following Williston's lead. Dr. S. P. Langiey and Mr. F. A. 

 Lucas, both of the Smithsonian Institution, have perpetuated 

 the error in their respective papers in the Annual Peport of 

 that Institution for 1901. 



In justice to Williston, it is perhaps only fair to quote him 

 verbatim (loc. cit.) : " As stated by me in the American 

 Naturalist, the type specimen of Pteranodon^ also collected by 

 myself, was incomplete, and the figures of it, as given by 

 Marsh, are faulty." This statement can not be gainsaid. The 

 type suffered through the rough methods of collecting 

 employed in those days ; but the following clause has been 

 shown above to be incorrect : " The sagittal crest is large, but 

 not nearly so large as it is figured by Marsh, the outline of 

 whose figure is undoubtedly wrong." 



To assign the cause of mistake on the part of another 

 writer may be considered a work of supererogation, yet I am 

 tempted to offer here a possible explanation of Williston's 

 misinterpretation of the sagittal crest of this reptile. At the 

 present time of writing, an incomplete Pterodactyl skull is 

 being worked out at the Yale Museum, which will in all 

 probability prove to be that of Nyctodactylus Marsh. The 

 crest, which is apparently entire, is of small size compared 

 with that of Pteranodon, the measurement from occipital 

 condyle to tip of crest being only 49'°'^, while the length from 

 occipital condyle to tip of beak was approximately 47'^". In 

 general, the skull compares favorably with that shown in 

 Williston's restoration of Nyctodactylus given in the Ameri- 

 can Journal of Anatomy, voL i, No. 3, May 26, 1902, where 

 he states that the outline is taken in part from a specimen of 

 Pteranodon Marsh, or Ornithostoma Seeley, as the genus was 

 then called. It is therefore fair to infer that the apparent 

 similarity of the two genera led Williston to draw uninten- 



