1870.] 417 [Hyatt. 



and said he was prepared now, after long and careful study, 

 to state that the Brachiopods were not mollusks, but true 

 articulates ; and that their proper place was among the worms, 

 forming a group near the tubicolous annelids. 



This communication will appear in full in the future pages 

 of these Proceedings. 



Mr. A. Hyatt acknowledged himself an unwilling convert. 

 He said their mutual labors to establish the name Saccata, 

 instead of Mollusca, had given him a deep interest in the 

 result of Mr. Morse's investigations. He spoke of the com- 

 plete evidence presented of his position, and alluded to JPho- 

 ronis Mppocrepia in confirmation of Mr. Morse's view of the 

 annelidan structure of Polyzoa ; the only difference between 

 Phoronis and the Polyzoa lying in the digestive system, the 

 termination of the intestine being probably near the posterior 

 end of the body, instead of near the mouth as in Polyzoa. 



Dr. Charles Pickering said, in the Feejee Islands the Lin- 

 gula was found abundantly in the brackish waters of the 

 estuary of a large river, which is barred at its mouth by 

 coral reefs. He also referred to the fact that the oldest geo- 

 logical Lingula was as perfect as those found to-day, as fatal 

 to much modern theorizing. 



The following paper was presented : — 



Geological Sketch of the Argentine Republic. 

 By Dr. G. A. Maack, Cambridge, Mass. 



Since the year 1789, when a complete skeleton cJ ~* T *athe- 

 rium was found in the bank of the river Lujan, one and a half 

 leagues southwest of Buenos Ayres, which was sent the same 

 year by the Marquis De Loreto, at that time governor of this Spanish 

 Vice-royalty, to Madrid, where it at present forms one of the most 

 valuable treasures of the Royal Museum of Natural History, and fur- 

 ther since the travels of the celebrated French and English natural- 

 ists, Mr. Alcide D'Orbigny and Mr. Charles Darwin, over the La 

 Plata States, the scientific interest in the nature of this large and 



PROCEEDINGS B. S. N. H.— VOL. XIII. 27 APRIL, 1871. 



