571 



Slated Ileethig, Decemher 2d, 1870. 



Dr. G. B. Wood, President, in the Chair. 



Present, fourteen members. 



A letter of acknowledgment was received from the R. 

 Danish Society of Sciences, dated November 5, 1870 (81, 82, 

 xiii. 3). 



Donations for the Library were received from the Prussian 

 Academy ; Silliman's Journal ; the Connecticut Academy ; 

 the American Oriental Society ; Mr. James J. Barclay, of 

 Philadelphia ; and Dr. Rushenberger. 



Dr. H. C. Wood presented for publication in the Transac- 

 tions of the Society a Monograph of the Fresh AYater Algas 

 of the United States, which was referred to a Committee con- 

 sisting of Dr. Carson, Dr. Bridges, and Mr. Durand. 



Dr. Pepper communicated " Observations upon a Skeleton," 

 exhibiting a unique case of Universal Hypostasis associated 

 with Osteoporosis, illustrated by DraAvings. Dr. Leidy, Dr. 

 Coates, and Dr. Allen were appointed a Committee to act in 

 conjunction with the Secretaries respecting the publication of 

 this paper. 



Prof Cope communicated a paper on the Fishes of the 

 Fresh Water Tertiary in Idaho, discovered by Capt. Clarence 

 King ; and another on the Adocid^e. 



Prof. Cope made the following verbal communication on 

 fossils, which he exhibited and described : — 



Prof. Cope exhibited vertebrae of two species of Pytlionomorpha, the 

 largest known to exist. One of these, Mosasaurus maximus Cope, from 

 the New Jersey Cretaceous, was represented by vertebree, whose centra 

 were 3.5 iuclies in diameter across the articular extremities. Those of 

 M. missuriensis Harl. measured 2.5 inches in a specimen of seventy-five 

 feet in length, according to W. E. Web'a ; so that the M. maximus prob- 

 ably exceeded that length. This measurement was also confirmed by 

 statements of persons engaged in digging marl in New Jersey. The 

 second species exhibited was still larger, and appeared to belong to the 

 genus Liodon. The diameter of the convex articalar extremity was more 

 than 5.0 inches, indicating a great length for the aniraa.', perhaps one 



A. p. S. — VOL. XI — 44e 



