152 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



bed of broken shells, making a true coqnina. In places this is 

 found well up in the hills or forming the tops of hills. Just 

 how it is related to the Reynosa is not known. 



The Reynosa, as shown by its relations to fossil if erous beds 

 above and below it, is Upper Pliocene and our idea is that the 

 Coquina is of similar age. 



Going southward w^e find, around Tampico and the Laguna 

 Viejo, beds of sandy clay with Ostrca virginica and a few other 

 shells of like recent affinities. Similar deposits occur in the 

 area between Tampico and Tuxpam and to the south of the 

 Tuxpam River. 



All of these deposits are more or less local in their distribu- 

 tion, and have not been studied sufficiently to permit a fuller 

 description. 



While no fossiliferous beds of Miocene or earlier Pliocene 

 age are known w^ithin the area here discussed, they do occur 

 farther south and more detailed work may discover extensions 

 of them in this region also. 



The nearest locality at which such fossils have been collected 

 and identified is Santa Maria Tatetla, Veracruz, about sixty 

 miles south of Nautla. This was described by Bose in Bulletin 

 22 of the Mexican Geological Institute. Both Bose and Vil- 

 larello state that a similar fauna is found in deposits occurring 

 near Actopam and Tezuitlan which lie between Santa Maria 

 Tatetla and Nautla. 



The following is from Bose's description: 



Santa Maria Tatetla is a native town in the Canton of 

 Huatusco and 25 or 30 miles northwest of the city of Veracruz. 

 It is situated in the bottom of a deep barranca at an elevation 

 of 349 meters on the bank of the Rio Santa Maria, which, after 

 uniting with several arroyos, forms the Rio Antigua and enters 

 the gulf near Antigua. The general character of the region is 

 that of an extended mesa almost perfectly flat, somewhat in- 

 clined towards the east and cut by numerous barrancas. To- 

 wards the north and west the mountain rises in sierritas made 

 up chiefly of Middle Cretaceous limestones and modern eruptive 

 rocks. The upper part of the mesa is mostly a conglomerate 

 of eruptive rocks horizontally stratified and in all probability 

 an upper Pliocene and Post-Pliocene Marine formation. Be- 

 neath these conglomerates there are outcrops of the Escamila 



