MEMOIRS 
OF THE 
C AORN JEG JU) MNOS Ue 
WOlbe JOG IN@, (8) 
NOTES ON OSTEOLOGY OF BAPTANODON. 
Wire A Description oF A NEw SPECIES. 
By CHarites W. GILMORE. 
During the season of 1903, while in the service of the Carnegie Museum, the 
writer collected from the marine beds of the Jurassic in the Freeze Out Mountains 
in Carbon County, Wyoming, quite a complete Baptanodon skull (No. 1441") and 
lower jaws associated with other parts of the skeleton. 
Through the courtesy of the Director, Dr. W. J. Holland,’ the writer was accorded 
the privilege of studying this specimen, thinking perhaps it would give some infor- 
mation regarding the obscure points in our knowledge of the anatomy of this 
interesting reptile. 
The skeleton like nearly all of the American Jurassic Ichthyosaurians was 
enclosed in a very hard limestone concretion® much seamed and cracked by expo- 
sure to the elements. 
Since publishing a paper on the Osteology of Baptanodon?* additional discoveries 
have thrown new light on the structure of this animal. It thus becomes necessary 
'Card catalogue number, Department of Vertebrate Fossils of the Carnegie Museum. 
2 My acknowledgments are especially due Dr. W. J. Holland, and I take this opportunity to express my appreciation 
of the many courtesies extended during the preparation of these notes. The text-figures were drawn by Mr. H. W. 
Hendley, of the U. S. National Museum, Washington, D. C. 
5 A recent letter from W. H. Reed, of the Museum of the University of Wyoming, informs me that during the past 
summer he collected a very complete Ichthyosaurian skeleton, which was quite free from the refractory matrix men- 
tioned above. He regards this specimen as coming from a lower horizon than those found in the concretionary layer. 
‘MEMOIRS OF THE CARNEGIE MuSEvM, Vol. II., No. 2, August, 1905. 
325 
