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bulletin: museum of comparative zoology. 



conjecture that he received some of them after the publication of his 

 two articles, or that he did not recognize them as belonging to Dorudon. 

 There is, indeed, no proof that they all represent that genus, but after 



examining them I am of the opinion that, with the possible exception of 

 the ribs, they all belong to Dorudon serratus, and probably to the same 

 individual. I base this opinion on the fact that they are all of one color 

 and are all filled with a green sand of uniform texture and color, and 

 that the size of the different parts appears to be properly proportional. 

 In order to bring the evidence as regards size clearly before the reader, 

 I have made a restoration of the skull, in outline, which is represented 

 in figures 1 and 2, one-eighth natural size. The parts actually present in 

 the Gibbes collection are indicated by heavy lines, and among them will 



be recognized those figured by Gibbes in 1845 and 1847. All these 

 parts are represented in Plates 1, 2, and 3, which are reproduced from 

 photographs. 



Gibbes recognized the fragment of the maxilla containing three 

 teeth to be such in 1845, but in 1847 he described and figured it, to- 

 gether with the premaxilla, as a part of the mandible. The right pre- 

 maxilla contains the third incisor and a part of the alveolus of the second. 

 The first incisor and the adjoining parts of the premaxilla are lacking, 

 and are restored in figures 1 and 2. Both premaxillae show the large 

 concavity in which the anterior end of the maxilla rests, but the nasal 

 branch above it is broken off, and is restored in the figures. The length 



