A New Ammonite Fauna of the Lower Turanian of Mexico 187 



in the lower Turonian in many cases where an exact determination of the 

 age of the beds has been possible. Varieties of this group have be.en de- 

 scribed from India, from different parts of northern Africa, as Egypt 1 

 and Tunis- ; from Portugal 3 , from Nigeria 4 , from Saxony"', and from Bra- 

 zil." It is therefore a universally distributed form which characterizes the 

 lower Turonian. 



To the same group of Pseudaspidoceras Footeanum belongs also the 

 species called by me Pseudaspidoceras an*, pedroanum White. It is still 

 nearer related to the Indian type than the former species, but differs by 

 its less strong ribs and the smooth ventral part. In all its characters it is 

 similar to the Ammonites pedroanus White and only differs in some de- 

 tails of the ornamentation. The similarity is so great that I have not been 

 able to separate the two forms specifically and have not united our speci- 

 men with the Brazilian species only because this latter form is still imper- 

 fectly known. ' . 



Our Vascoreras aff. adonense is certainly very similar to the Portuguese 

 type from the Turonian, but differs by its suture and the form which is 

 still more evolute. 



The form of greatest stratigraphic interest in our fauna is perhaps our 

 Fagesia Haarmanni n. sp. It belongs to the group of Fagesia superstes 

 Kossmat, but differs from the type as well as from all the other species of 

 this genus by its more evolute form. The species belonging to this group 

 are limited to the Turonian and especially to the lower part of it. The 

 type was described from the Utatur group of India, 7 and a very typical 

 form has also been found in Tunis 8 ; a nearly related species has been cited 

 from the Turonian of Portugal. 



Fagesia Pervinqieri n. sp. is a very characteristic species and belongs to 

 that group of Fagesia which loses its ribs in a rather juvenile state of 

 growth ; the type of this group is Fagesia tevesthensis Peron. Our species 

 differs from the type by its higher and less broad whorls. According to 

 Pervinquiere Fagesia Rudra Stoliczka 10 belongs also to this group; this 



Zittel, Lib. Wuste, p. LXXIX (A. cfr. Footeanus) Eck, Turon in Acgypttn. p. 3^0 

 (Acanthoceras cfr. Footeanum). 



2 Pervinquiere. Paleontologie Tunisienne, p. 314 (Mammites Salmuriensi*) . 

 'Choffat, Especes nouv. ou peu conn., p. 66 (Acanthoceras cfr. Foolfanum', 

 4 Woods, Cret. dep. Northern Nigeria, p. 283 (Mam-mites [Pseudaspidocerat] up.) 

 ^Petrascheck, Amm. d. sachs. Kreideform., p. 144 (Mammites f 

 "White, Brazil, p. 212 (Ammonites pedroanus). 

 'Kossmat, Sudindische Kreideform., p. 133, pi. 17, fig. 1. 

 "Pervinquiere, Palecntologie Tunisienne, p. 322, pi. 20, fig. 1-3. 

 Choffat, Especes nouv. ou peu conn., p. 69, pi. 10, fig. 4. 

 '"Stoliczka, Ceph. Cret. Rocks India, p. 122, pi. 60. 



