282 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY. 



the same, or about 45° west. Counting from above you would thus 

 have : 



Conglomerate, 



Lime, 



Conglomerate, 



Lime, 



Sandstone. 

 This might indicate two distinct periods of formation, but as the con- 

 glomerate on both sides of the lime seems to be entirely identical and 

 the lime itself differs widely from the stratified lime farther east, and 

 shows no signs of fossils, I would assume it to be of much later origin 

 and due to infiltration. 



The fossils I have been able to collect are not numerous, but I trust 

 they will be sufficient to determine their age. 



The reported coral reef at Aguas Calientes in Cartago, which was 

 visited by request, proved to be calcareous tufa. The formation is 

 going on to-day, and is due to precipitation of lime and magnesia from 

 thermal springs in the vicinity. It looks at a distance somewhat like 

 a coral reef. 



