16 Annals of the Carnegie Museum. 



value, and that they were characteristic of the Tertiary beds along the 

 Brazilian coast. It is true that there are good reasons for considering 

 many of the colored beds of this coast as Tertiary, but it is my opinion that 

 the colors are accidental, and that they also extend into the Cretaceous 

 beds, and occasionally into even older beds as well. At a great many 

 exposures examined along this coast the evidence all points to the fact 

 that the beds, which have long lain beyond the reach of weathering, retain 

 their dull gray and drab colors, while those which have been acted upon 

 by surface-waters and oxidizing agencies have usually been profoundly 

 affected. These points are fairly well brought out by the exposure at 

 the cliffs south of the Rio Camaragibe. There the rocks at the base 

 of the bluff are well exposed and show clearly the stratification and the 

 landward dip of the beds. These lower beds range in color from drab 

 through dark brown to almost black, but about three or four meters above 

 the level of high tide the bedding planes fade out, and the drab colors 

 give place to the yellow, red, and mottled colors which continue to the 

 top of the bluffs. Especially striking is the fact that these upper colored 

 beds have the general appearance of being horizontally stratified, although 

 the stratification planes are more or less obscure and uncertain, while the 

 lower beds are well defined and have marked dips. Believers in the 

 theory of the Tertiary age of the colored beds might urge that these facts 

 point to an unconformity between the strata at the bottom and the top. 

 However, a close inspection made with this point in mind not only failed 

 to disclose an unconformity, but showed that the stratification of the 

 lower beds merges very gradually into those which are highly colored, and 

 finally disappears altogether. In other words the weathering process has 

 not only altered the color of these sediments; but it has obscured the 

 stratification, so that the original bedding, in some instances at least, 

 cannot be made out. 



Fossils from the Alagoas Sediments. — Fossil plants have been seen in 

 the dark bituminous shales which commonly underlie the highly colored 

 sandstones and clays forming the bluffs along nearly the entire coast of 

 Alagoas. At every place where these plant remains have been seen the 

 plants appear to have decayed and then to have been washed back and 

 forth until they were ground into unrecognizable fragments. At all events 

 a diligent search for recognizable remains of plants has thus far failed to 

 discover any. 



Diatoms. — -Specimens of the bituminous shales collected at Riacho Doce 

 were submitted to Mr. Wm. A. Terry, of Bristol, Conn., who kindly 



