186 University of Texas Bulletin 



their forms are so characteristic that they easily allow the determination of 

 the age of these beds. In the following table we shall compare them with 

 related species of other countries. 



Horizon II. 



Turonian 



Species from Cerro del Macho Related species Lower Middle 



Mammites mohovanensis n. sp. M. nodosoides Schlotheim 



Pseudaspidoceras aff. Footeanum P. Footeanum Petrascheck + 



Pseudaspidoceras aff. pedroanum P. Footeanum Stoliczka + 



Vascoceras aff. adonense V. adonense Choffat + 



Fagesia Haarmanni n. sp. F. superstes Kossmat + 



Fagesia Pervinquieri n. sp. F. tevesthensis Peron + 



All the species of this horizon indicate that it belongs to the lower Tu- 

 ronian or Salmurian. It s true that Choffat cites his Vascoceras adon- 

 ense from the middle Turonian, but I believe that this middle Turonian of 

 Portugal belongs in reality still to the Salmurian, i.e., the lower Turonian. 

 The occurrence of forms belonging to the groups of Fagesia superstes, Fa- 

 gesia tevesthensis, Mammites nodosoides, Inoceramus labiatus, etc., ap- 

 pears to be quite decisive for the determination of the age of those beds. 

 In our own case we have to consider that this horizon lies immediately 

 above what we take to be upper Cenomanian ; there seems to be no reason 

 to doubt that our Horizon II represents the very lowest Turonian. This 

 idea is confirmed also by the fauna of Horizon III, which will be discussed 

 farther on. 



Our Mammites mohovanensis is very nearly related to M. nodosoides 

 Schlotheim. It differs principally in its broader cross section; still more 

 similar to our species is Mammites conciliatus Stoliczka, which belongs to 

 the same group, the main difference consisting in its more evolute form 

 and some details of ornamentation. In these details our form is still more 

 similar to a form determined by Fritsch as Mammites conciliatus which in 

 reality occupies an intermediate position between our species and that of 

 India. 



The species which we have called Pseudaspidoceras aff. Footeanum Pe- 

 trascheck is much less related to the type of this group (P. Footeanum 

 Stoliczka) than to the specimens from the lower Turonian of Saxony de- 

 scribed by Petrascheck, on account of the more rounded and less subquad- 

 rangular cross section, as well as the greater height of the whorl. This dif- 

 ference may be explained in our section by its large size; comparing the 

 different figured forms of P. Footeanum we see that the adult specimens 

 tend to lose their quadrangular cross section. This group has been found 



