60 University of Texas Bulletin 



The Del Rio clay surrounding the Solitario Uplift contains a rich assort- 

 ment of brown limonitic fossils, including *Engonoceras sp., *Turrilites 

 (two species), *Turritella sp., gastropods, *Nucula sp., *Tapes sp., *Nodo- 

 saria texana Conrad, and other fossils. 



It may be mentioned that these limonite faunae in Texas are not confined 

 to the Comanchean, since & rich fauna was found in the Terlingua beds 

 (Taylor marl equivalent) about five miles north of the crossing of the 

 Alpine-Terlingua road through Terlingua Creek, Brewster County, Texas. 

 This fauna includes: *Turrilites sp., *Baculites sp., *Ptychoceras sp., 

 *Desmoceras sp., *Trochosmilia sp., *Lingula sp., *Lunatia sp., *Natica sp., 

 *Nerinea sp., numerous other gastropods, and fish teeth and vertebrae. 



Bose 1 found a rich Vraconian fauna in limestone blocks covering small 

 hills just west of Camacho, Zacatecas, between this station and the Trin- 

 idad mine, and west of Opal, Zacatecas, iri the core of an anticlinal hill 

 consisting of thin-bedded limestone with lenses and concretions of chert. 

 These fossils are mainly silicified, but are! cited here on account of their 

 striking resemblances to the pyrite fossils described in this paper. The 

 fauna includes typical Vraconian genera, as Phylloceras, Lytoceras, Macro- 

 scaphites, Hamites, Hamulina, Ptychoceras, Diptychoceras, Anisoceras, 

 Turrilites, Baculites, Desmoceras, Acanthoceras, Ancycloceras, Toxoceras, 

 Crioceras, Scaphites, Schloenbachia, Brancoceras and Exogyra. 



SUMMARY OF PYRITE FAUNAE . 



The Washita marl and clay faunae contain distinctive assemblages of 

 ammonites, Crustacea, starfishes, echinoids, gastropods, pelecypods, corals, 

 and other fossils. The Crustacea are preserved partly with the original 

 integument and partly with limonite replacement. The other fossils are 

 in part calcitic, but mainly limonite and hematite pseudomorphs and casts 

 of the interior of the -original shell. 



Ammonites: These are very distinctive for each fauna. Species of 

 Schloenbachia abound in each marl and clay formation. Acanthoceras is 

 found in the Denton, Pawpaw and Grayson faunae, but not in the Duck 

 Creek. Hamites are abundant in the Duck Creek marl and present in 

 the other formations. Turrilites abounds in the Pawpaw and is not 

 known with certainty below it. Flickia, Hamulina, Baculites and Puzosia 

 are known only from the Pawpaw clay. 



ose, On some new Cretaceous Faunas from Mexico, Univ. Texas Bull, (in press). 



