A New Ammonite Fauna, of the Lower Turanian of Mexico 215 



With respect to its external form our species resembles Vascoceras 

 adonense Choffat, but this latter species shows nodules on its umbilical 

 border, while these are entirely missing in our specimen. This might be 

 explained by the stage of development, our individual being much larger 

 than that of Choffat, but our species is certainly much more evolute. A 



Figure 2. Suture, Vascoceras angermanni n. sp. (above) and Vascoceras aff. adonense 

 Choffat (below). 



fundamental difference can be found in the suture. In the type species 

 we find on the umbilical border the first lateral saddle, but we see that 

 in our specimen the second lateral saddle is in this place. In its general 

 character our suture is much more similar to that of Vascoceras Gamai. 



Our species therefore has to be considered as a new form which in its 

 external figure resembles Vascoceras adonense while the suture places it 

 in the vicinity of Vascoceras Gamai. We can not give it a new name 

 because the specimen is too badly preserved. 



Number of specimens: 1. 



Age: Lower Turonian (Salmurian), lower horizon. 



