CHIAPAS, TABASCO, AND PENINSULA OF YUCATAN 94 1 



along the northern base of the Sierra Madre. The beds are a 

 little inclined to the north in many places where I was able to 

 ascertain the dip. They do not lie conformably over the Car- 

 boniferous limestones, and apparently their deposition occurred 

 after the primary formation of the Sierra Madre, along the shores 

 and bottom of a sea, later than the Carboniferous but before the 

 Cretaceous, and that they have undergone few dislocations or 

 alterations. 



I cannot give any exact data on the relative age of these 

 beds because I have found no fossils in them. Perhaps they are 

 deposits of the Triassic period, the latter having been found in 

 the Republics of Honduras ' and Nicaragua.^ 



The formations i to 4 occur only in the southern part of 

 Chiapas. The northern parts of the same state are made up of 

 more recent sedimentary rocks, of the Cretaceous and Tertiary. 



5. Cretaceous limestone. — In the greater part of the northern 

 region of Chiapas are limestones and dolomites, both of the 

 Cretaceous period. I have found Rudistes, Radiolites sp., and 

 Sphefidites sp. between San Cristobal, Las Casas, and Teopisca, 

 between Teopisca and San Lazaro, between San Bartolome de 

 los Llanos and San Jose de La Canoa, between Santa Isabel and 

 Campana (Department of Comitan, near Comitan), between El 

 Calvairo and Chiapa, between San Vicente and Soyalo, where I 

 also met with some Nerineas, near to San Cristobal, Las Casas, 

 and between Yochiu and Tenejapa. All these points are situated 

 in the southern part of the Cretaceous belt. 



In the northern portions of the same zone I could not find 

 any traces of Rudistes, but I found remains of fossil corals in 

 various places, as in La Puncta, the Catate and Salvador rivers, 

 between Sabanilla and Tila, and between Tila and Tumbala. 



These organic remains have not been examined with suf- 

 ficient care as yet to enable one to say whether the limestones 

 containing the rudistes and those containing the corals belong 



' Dr. R. Fritzgartner, Kaleidoscopic views of Honduras, in Honduras Mining 

 Journal. 1891. Num. 6-8. Tegucigalpa. 



= Dr. Bruno Micrisch, Eine Reise querdurch Nicaragua, in Petermann's Mitteil- 

 ungen. Gotha, 1895. I^P- 57. et seq. 



