NATURAL SCIENCES OF PHILADELPHIA. 97 



April 10th. 

 Mr. Lea, President, in the Chair. 

 Thirty-eight members present. 



Mr. Lea remarked that he had recently received from Prof. J. Wyman 

 specimens in alcohol of two s*pecies of Anodonta from the Uruguay River, 

 South America, descriptions of the soft parts of which he had made, and in- 

 tended, at a future time, to publish in the Journal at length ; but he wished 

 at present to mention that he had found a form of Palpi (mouth lips) different 

 from any of the (Jnionidce which had come under his notice from any other 

 part of the world. The form of the Palpi heretofore described have always 

 been obliquely or transversely elliptical or subtriangular, while these two spe- 

 cies, An._Wym.anii, Lea, and.4n. lato-marginata, hen,, are round, and the pair on 

 either side only joined above, the edges being entirely free. It is greatly to 

 be regretted that more or all the South American Unionidce could not have 

 been examined, as regards their soft parts, to ascertain if this difference of 

 form of the Palpi should be persistently different in all the South American 

 Unionida;, or only with this member of the family the Anodontai. 



April 17th. 

 Mr. Lea, President, in the Chair. 



Fifty-six members present. 



The following papers were presented for publication : 



" Monograph of the Genus, Lubrisomus, of Swainson, by Theo. Gill." 



" Monograph of the Genus Labrax, of Cuvier, by Theo. Gill,'' 



" Monograph of the Philypni, by Theo. Gill." 



" Notice of Geological Discoveries, made by Capt. J. H. Simpson, 

 Top. Engineers, U. S. Army, in his recent explorations across the Con- 

 tinent." 



11 Catalogue of Birds collected during a survey of a route for a ship 

 canal across the Isthmus of Darien, by order of the Government of the 

 United States, made by Lieut. N. Michler, U. S. Top. Engineers, 

 with notes and descriptions of new species, by John Cassin." 



And were referred to Committees. 



Mr. Lesley described a boulder of gneiss, eight feet high, on the summit of 

 one of the Orange Co. highlands, in the State of New York, which was sup- 

 ported by four smaller rocks, so that it was lifted about a foot above the floor 

 of nearly horizontal gneiss, forming the top of the mountain. One of these 

 supports was a hard blue limestone, from the crust of which Mr. Lesley ob- 

 tained numerous fossils, among which was probably the Orthis costalis, (Hall,) 

 of the Chazy Limestone. Another block of limestone, also fossiliferous, lay 

 not far away, and a few small pieces of a reddish sandstone like that of certain 

 bands in the Oneida Conglomerate ; but with these exceptions, there was neither 

 drift nor diluvial striae visible, but here and there large blocks of gneiss. 

 The whole surface of the exposures, which were numerous and many hundred 

 feet square, has been weathered down 2 or 3 inches, as is evident from the 

 ridges of refractory quartz veins, which have successfully resisted the atmo- 

 sphere. On this weathered surface occur what have been called the footmarks 

 of animals ; but these are nothing else than weathered-out nodules of rock 

 more ferruginous than the rest. The locality is two miles east of Southfield 

 Station, on the New York and Erie Railroad. Mr. Lesley and his brother were 

 accompanied and guided to the locality by Mr. T. B. Brooks and Mr. Jenkins, 

 two excellent local geologists and mineralogists, living in the village of Munroe. 



I860.] 6 



