64 KNOWLTON 



The fifth species— Trionyx foveatus — is the only one that appears 

 to be distributed into higher beds, but it will be recalled on refer- 

 ring to the discussion of this species on page 53, that, while it has been 

 reported from Long Lake, North Dakota, Hell Creek, Montana, 

 and near Denver, Colorado, both Hatcher and Hay have expressed 

 the opinion that there may be two and possibly three species confused 

 under this name, each being confined to one of the three horizons 

 involved. 



The following forms, although having their types from beds 

 higher than the Judith River formation (Arapahoe, Lance formation 

 etc.), appear on more or less questionable evidence to have ranged 

 downward into the Judith River : 



Plastomenus coalescens (?) 



Adocus Uneolatus (?) 



Aspideretes beecheri (?) 

 The reasons why these are regarded as questionably present in 

 the Judith River formation are set forth in the discussions of these 

 species in the preceding pages. Not a single one has a clear title. 



Conclusions. 



1 . The Judith River fauna has had accredited to it by Hatcher 

 and Hay at least sixteen species of fossil turtles. 



2. Of these sixteen species seven are to be excluded on the suffi- 

 cient ground that they do not occur in beds of Judith River age. 



3. Of the nine remaining species that may have a more or less 

 valid claim to membership in the Judith River fauna, five have 

 their type localities in beds of Judith River and Belly River age, and 

 four in horizons above that of the Judith River. 



4. Of the five typically Judith River species, four are absolutely 

 confined to these beds, while the remaining one which has an alleged 

 higher range, is shown to be probably a composite species possibly 

 including three species which correspond respectively to the three 

 horizons involved. 



5. Of the four species, the types of which came from post- Judith 

 River beds, and which are claimed to range downward into the 

 Judith River, not a single one enjoys a clear title to be so regarded. 



