ABSTRACTS OF PAPERS 131 



ties, known as Calcisphara robusta Williamson. They occur by the score, and 

 lumps of the shale may be found in wliich large numbers of them are massed 

 together. A few have been isolated on which the spiral lines are double. 



Among the foraminifera a rotaline form is fairly common. It seems to be- 

 long to a new genus. Lagena and Saccamina are rare ; the latter gives evi- 

 dence of occurring in chains, as illustrated by Brady and others. A GloMg- 

 erina-like species is found sparingly at one or two horizons. Minute tetracti- 

 nellid spicules represent the sponges. 



Oonodont teeth referable to the genus Pol i/gna thus occur. These micro- 

 scopic translucent worm remains are beautifully preserved and are among the 

 smallest forms recovered. Small, slender, annulated shells of TenfacuUtes are 

 common in nearly every pan of the marl. Their exquisite hyaline tips are pre- 

 served in many cases. Some of tliese are doubtless the young of a new species 

 of Tentaculites from the same beds and which reach a lengtli of five milli- 

 meters or more. 



The screenings are rich also in shells of tiny ostracods. Some of tlie genera 

 are abundant and are represented by more than one species ; a few, notably 

 Entomis, are very rare. The commonest genera are Bnirdia, Kirlchyina, 

 Biithocypris, Ci/pridina, and Bci/richia, while there are several forms which 

 have not been generically determined. 



The meeting then adjourned for luncheon. 



PRESIDENTIAL ADDRESS 



At 2 p. m. the Society met to hear the address of the retiring Presi- 

 dent of the Paleontological Society, entitled 



OlilGIN OF THE SOUTH AMERICAN FAUNAS 

 PRESIDENTIAL ADDRESS BY F. B. LOOMIS 



Following this address, the reading of the papers prepared for the 

 symposium and arranged for the meeting was taken up. 



SYMPOSIUM ON CRITERIA AND METHODS EMPLOYED IN PALEONTOLOGIC 



RESEARCH 



CRITERIA FOR THE DETERMINATION OF THE CLIMATIC ENVIRONMENT OF 



EXTINCT ANIMALS 



BY E. C. CASE 



CRITERIA FOR DETERMINATION OF CLIMATE BY MEANS OF FOSSIL PLANTS 



BY F. H. KNOWLTON 



METHODS OF DETERMINING THE RELATIONSHIPS OF MARINE INVERTE- 

 BRATE FOSSIL FAUNAS 



BY' CHARLES SCHUCHERT 



CRITERIA FOR SPECIES, PHYLOOENIES. AND FAUNAS OF TRILOBITES 

 BY P. E. RAYISIOND 



