102 



different from those of birds of the present day. Mr. Blake, a 

 member of our Society, who has visited these deposits, has a shell 

 found in the Guano, very much resembling the Crepidula fornicata 

 of this coast, but not in any way fossilized. On this coast it never 

 rains, so that the deposits of manure are not, like those on other 

 coasts, annually washed away. 



Mr. Tescliemacher next exhibited dendritic appearances, 

 artificially produced, resembling, in their forms, those of 

 the Dendritic Manganese from Newton, Mass. 



They were formed by laying finely pulverized earth on a slip 

 of glass, moistening it with a few drops of water, and then cover- 

 ing it with a thin plate of mica without further pressure. On the 

 gradual evaporation of the water, the particles of earth, under the 

 slight pressure of the mica, aggregated themselves into these den- 

 dritic forms. 



Mr. Stoddard read a paper entitled " An Hypothesis to 

 explain the Changes of the Surface of the Earth," which, 

 on motion of Dr. Gould, was committed to a select Com- 

 mittee for examination and report. Dr. C. T. Jackson, Dr. 

 Binney and Mr. Emerson were chosen the Committee. 



Dr. Binney said he had lately visited Washington, and 

 stated that an unfavorable impression which he had receiv- 

 ed of the value of the collections of specimens in Natural 

 History made by the late Exploring Expedition, and the care 

 bestowed on their preservation, had been entirely removed. 



Rev. Francis Mason, missionary in Burmah, was elect- 

 ed a corresponding member. 



ADDITIONS TO THE LIBRARY. 



Annals and Magazine of Natural History, for February, 1843. 

 Courtis Fund. 



Description des Cancellaires Fossiles des Terrains Tertiaires du 

 Piedmont, per L. Bellardi. 4to. pam. Turin. 1841. Dr. C. T. 

 Jackson. 



Histoire Naturelle des Rainettes, des Grenouilles et des Cra- 

 pauds, par Daudin. From S. S. Haldeman. 



Illustrations of British Ornithology. By P. J. Selby. 8vo. 2. 

 Edin. Exchange. 



