102 THE NAUTILUS. 



folding extended from the Pyrenees Mountains in Spain to the 

 Himalayas in Asia. In America the union of the North and South 

 Americas, the fusion of the island of Florida with the mainland* 

 which was again severed towards its close. 



As we would naturally expect, a series of such great changes 

 would have some great effect upon the direction of oceanic currents. 

 It is to this that an appeal has been made for the explanation of the 

 uniqueness of our Atlantic coast Miocene faunas. This fauna is one 

 typically developed in cold waters. This being shown especially 

 well by the abundance of Astartidoe, Ledas and of such Venericardias 

 related to our recent Venericardia borealis. The warm- water- 

 loving series of the Oligocene retreated to the Antillean region, to 

 return again towards the close, of the Miocene and in the Pliocene, 

 when conditions again became favorable to them, to retreat again 

 before the general refrigeration which ushered in the Pleistocene 

 glacial advances. Also further proof of a cold oceanic current creep- 

 ing south along our coast is to be noted that the Miocene floras of 

 the adjacent mainland indicate a warm, mild climate. 



In the course of paleontologic work, it became rather desirable to 

 obtain some immature shells of certain species. In order to do so I 

 began the examining of the sand and marl contained inside of closed 

 valves of several large bivalve shells, amongst which was a specimen 

 of Melina (Perna) maxillata (Deshayes) from the Choptank River, 

 Maryland. In so doing, two small but beautifully preserved valves 

 of a small Triyoniocardia were discovered which later were identi- 

 fied as Cardium (^Trigoniocardia) galvestonense Harris. They are 

 figured on plate VI, figs. 11, 12. 



This species was first described by Professor G. D. Harris from 

 specimens obtained from the deep well drillings of the Galveston 

 Artesian well. 1 Specimens from there are figured, PI. VI, figs. 8, 

 9. The maximum depth attained in this well is 2,920 feet of which 

 the interval between 2,158 and 2,920 feet was referred to the Upper 

 Miocene. This fauna is tropical in its make-up, differing conspicu- 

 ously from the cold Chesapeake fauna which at the same time ex- 

 tended into the Gulf of Mexico, through the Suwanee straits which 

 separated Florida from the main-land. With the typical expression 



1 BuIl. of American Paleontology. Vol. I, No. 3, p. 91, pi. 1, fig. 3, 3a. 

 Dec. 2, 1895. 



