384 THE CRETACEOUS AISTD TERTIARY GEOLOGY 



alternately cover and expose them to the air and sunshine. These same beds are 

 exposed also on the opposite side of the river at a place called Jaque, where the 

 stone was formerly quarried at low tide. Here, however, the rocks are harder than 

 those at the Lastro exposure, the fossil fauna being the same. 



The rocks at Jaque are oolitic, of a light-brown color near the surface, but where 

 they have been blasted, or their interior pails arc unaffected by weathering, they have 

 a bluish-gray color. 



Rocks similar to those found at the Lastro and Jaque occur from two to three 

 miles further down on the west side of the stream. Here too tJie black flints which 

 seem to have weathered from some limestone beds are widely scattered. The beds 

 from which the flints have been dei'ived overlie the oolitic rocks exposed at Lastro 

 and Jaque. On the east side of the stream the rocks overlying the oolitic beds are 

 soft limestones such as are exposed about Porto da Rede. On the west side the 

 soft limestone beds are more or less flexed. 



The fossils most abundant at the Lastro are conchifers, cephalopods and echi- 

 noids. There were found here sixteen siiecies of conchifers, of which number ten are 

 new to science; nine species of cephalopods, six of which are new; ten species of 

 echinoids, nine of which are new. Gastei'opods are remarkably scarce, but two spe- 

 cies having been found here, both of which are new. 



Pedreira de Jono Pereira.'^' 



This quarry is about two miles east of Maroim. The rock is a soft, ci'eam-colored 

 to yellow, oolitic limestone, affording many imperfect specimens of cephalopods. 

 The rock is so soft that it is quairied in blocks by cutting trenches in it with picks. 

 The fossils are bivalves and cephalopods. Three species of the former and three of 

 the latter have been found here, all of Avhich are new to science. The beds have a 

 southerly dip. 



Oarajdu. 



This locality is immediately north of the town of Maroim, and is interesting as 

 containing the i-ocks from which one of the conchifers described by Dr. White as of 

 Jurassic aspect (Aucella hraziliensis) was obtained. Most ol' the fossils obtained 

 here ai-e Ci^phalopods {Ammonites liopTcinsi) and were broken fi-oni compact limestone 

 blocks whei-e they had l)een separated by disintegration from the main beds, which 

 crop out here and there about the fields. These beds overlie those of Aroeira, Las- 

 tro, Ja(pie, Gambarobe, etc., all of which arc oolitic. 



*Thi8 locality is ■tttongly given in V>t. AVliilc'.s I'aleoiilology us .]o;lo Forroira in some places, while in others it 

 ha3 the correct spelling. 



