210 Maury — Porto Rican Tertiary Formation. 



sented before the Geological Society of America, in 1915, 

 on "Stages in the Geological History of Porto Rico," 4 

 remarked that the majority of the fossils collected by him 

 in Porto Rico were gathered from the lignitic shales and 

 white limestone of the Yonnger Series. Only a very 

 brief examination had been made by Dr. Reeds of his col- 

 lection, bnt he noted that the sea nrchins indicated a "late 

 Eocene or Early Oligocene age." 



In the discussion following Dr. Reeds 's paper, Mr. 

 Edwin T. Hodge said that he found on Sierra Cayey a 

 coral characteristic of the Edwards formation of the 

 Gnlf, and some miles farther south, "the lower portion 

 of a Venericardia alticosta index for the Chickasawan and 

 Glaibornian of the Gnlf. ' ' Hodge stated that the Creta- 

 ceous and Eocene strata in which these fossils were found 

 had been peneplained and the later limestones deposited 

 upon this peneplain. From fossils collected by Dr. Ber- 

 key and studied by Dr. Marjorie O'Connell, Hodge said 

 that we knew the later limestones to be of Oligocene age. 



Dr. Reeds in a paper on "Porto Rican Localities Yield- 

 ing Vertebrate Fossils" 5 described finding remains near 

 San Sebastian and Juana Diaz. He separated the San 

 Sebastian and the Juana Diaz shales from the Arecibo 

 formation, and applied the name Collazo shales to the 

 former, because of their typical occurrence on Rio 

 Collazo. 



Dr. W. D. Matthew identified one of the vertebrate 

 fossils from the Juana Diaz shales, as the jaw of the 

 European Oligocene and Miocene Sirenian genus Hali- 

 therium and described it as H. antillense. 6 



Mr. D. R. Semmes 7 referred the Arecibo limestone to 

 the Upper Oligocene and the San Sebastian shale to the 

 Lower Oligocene. 



Dr. Anna I. Jonas made preliminary identifications of 

 the Porto Rican collection at the American Museum 

 referring many of the mollusca to Claibornian and Jack- 

 sonian species. 8 Her identifications are, unfortunately, 

 exceedingly erroneous. She lists twenty-one of those 

 identified as Gulf State Eocene and twenty as Gulf State 

 Oligocene species, but refers none to any Antillean fossil 



4 Bull. Geol. Soc. Amer., 27, p. 84, 1916. 



5 Ann. New York Acad. Sci., 26, p. 437, 1915. 



6 Op. cit., p. 439; and 27, pp. 23-29, 1916. 



7 Ann. New y or k Acad. Sci., 27, p. 279, 1917. 



8 Ann. New York Acad. Sci., 27, p. 281, 1917. 



