212 Maury — Porto Rican Tertiary Formation. 



Faunal Groups Represented. 



(1) The first faunal group differentiated was that of 

 the Quebradillas limestone. As one by one the familiar 

 Bowden and Santo Domingan Miocene species were iden- 

 tified by actual comparisons with specimens from Santo 

 Domingo and Jamaica, this horizon became a certainty. 

 Such forms as Phos costatus Gabb, Phos fasciolatus Dall, 

 Murex messorius Sowerby, Marginella coniformis 

 Sowerby, Olivella muticoides (Gabb), Drillia consors 

 (Sowerby), Haminea granosa Sowerby, Divaricella pre- 

 varicata Guppy and Malea camura Guppy indicated very 

 strong bonds of relationship. A very beautiful forami- 

 nifer similar to one I found in the Dominican beds was 

 also present though rare. 



As yet, however, I have not been able to satisfactorily 

 distinguish in northern Porto Rico the two formations 

 that we found in northern Santo Domingo and designated 

 as the upper or Sconsia and the Lower or Aphera forma- 

 tion. Hence it seems best to refer the Quebradillas fauna 

 to the Bowden which also contains mingled elements. 



A striking and very common species of the Quebradil- 

 las limestone is Metis trinitaria from the Caroni Series 

 of Trinidad, from Barbuda, and Santiago de Cuba. This 

 species is not reported from Bowden, nor did we find it 

 in our sections in Santo Domingo,, but the shell in the 

 Heneken collection from that island, called Tellina bipli- 

 cata by Guppy, was probably this Metis. 



(2) The next faunal unit differentiated was that of the 

 Orthaulax. This was kindly examined by Dr. Dall who 

 thought it a new species, nearest to Orthaulax pugnax. 

 As Dr. Eeeds found it near Aguadilla, I am naming it 

 aguadillensis in my forthcoming detailed report. No 

 shells were found associated with it, only a single sea 

 urchin that has been submitted to Dr. R. T. Jackson but 

 not yet reported on. 



(3) The most peculiar fossils in the collections are 

 very large internal molds of a turreted shell apparently 

 an enormous Cerite. These seemed worthy of sectional 

 rank as they differ in a number of respects from the 

 subgenus Campanile, and I am suggesting for them a new 

 section Portoricia. 



This horizon with the great Cerite, Dr. Reeds assures 

 me, from his field observations, lies below the Orthaulax, 



