: GILMORE: OSTEOLOGY OF BAPTANODON (MARSH) 79 
Dr. F. B. Loomis’ in a later paper proposes to confine the term Baptanodon 
Beds to the single layer in which the remains of these reptiles are found. Hatcher’ 
has justly contended that the duplication by giving new names to old and well 
known formations, “tends to augment still further the confusion which already 
exists in our geologic formation names,’ and this would appear to be another 
instance in which the old and generally accepted term should be retained in its 
original meaning. 
These beds have been briefly described by Knight as follows : 8 a Composed of 
bands of shale, limestone, sandstone, and clay. The limestones are usually shaly. 
The limestone beds are quite thin, but usually fossiliferous. The clays and shales 
usually contain large concretions which contain both vertebrate and invertebrate 
fossils. Septaria are common. ‘The invertebrate as well as the vertebrate faunas 
are only partly known. ‘This has been largely due to the fact that the richest fossil 
localities are where the concretions are well developed and until recently not 
many of these were known.” 
The following is a fairly complete list of the fossils described from the marine 
Jurassic of this country. 
INVERTEBRATES. 
Astarta packardi, White. ~ Modiola sp. 
Belemmnites densus, M.,& H. ; Ostrea engelmanm, Meek. 
Cardioceras cardiformis, M. & H. Pentacrinus asteriscus, M. & H. 
Cardioceras cardiformis, var. distans, Whitf. Pholodomya kingi, Meek. 
Comptonectes bellistriata, Meek. Pleuromya subcompressa, Meek. 
Comptonectes extenuata, M. & H. Pinna sp. 
Gryphea nebrascensis, M. & H. Pseudomonotis curta, Hall. 
Dentalium subquadratus, Meek. Pseudomonotis orbiculata, Whitfield. 
Goniomya montanaensis, Meek. Tancredia cf. extensa, White. 
Grammatodon inornatus, M. & H. Tancredia ef. inornata (M. & H.), Whitf. 
Tima sp. Tancredia warrenana, M. & H. 
Lingula brevirostris, M. & H. Thracia weedi, Stanton. 
VERTEBRATES. 
Baptanodon natans, Marsh. Megalneusaurus rex, Knight. 
Baptanodon marshi, Knight. Plesiosaurus shirleyensis, Knight. 
Baptanodon discus, Marsh. Pantosawrus striatus, Marsh. 
Cimoliosaurus laramiensis, Knight. 
5 Loomis, F. B., ‘‘On Jurassic Stratigraphy in Southeastern Wyoming,’’ Bull. of Am. Museum of Nat. History, 
Vol. XIV., article XII., pp. 189-197, June, 1901. 
THatcher, J. B., Memoirs of Carnegie Museum, Vol. I1., No. 1, November, 1903, p. 67. 
8 Tit. cit., p. 385. 
