NATURAL SCIENCES OF PHILADELPHIA. Ill 



April \th. 

 Mr. Lea, President, in the Chair. 



Forty-nine members present. 



The following were presented for publication in the Proceedings: 



Ichthyological Notices by Charles Grirard, M. D. 



On (he primary divisions of the Salamandridae, with a description of 

 two new species, by E. D. Cope. 



Description of twenty one new species of Exotic Unionidae, by Isaac 

 Lea. 



Description of two new species of Uniones, from Georgia, by Isaac Lea. 



Dr. Leidy remarked, that Mr. Jos. B. Hanson, an intelligent merchant of 

 this city, had recently addressed to him a note, to call at his warehouse and 

 examine some masses of the so-called Sombrero guano, containing fossil bones. 

 Two large masses of this substance, now on the table and presented to the 

 Academy by Mr. Hanson, include a number of turtle bones, among which the 

 posterior portion of a sternum of an individual is well preserved. The included 

 bone fragments significantly point to the origin of the rock, imported as a 

 manure rich in phosphates, from the island Sombrero, W. I. This island, 

 situated about 130 miles east of Porto Rico, Mr. Hanson informs us, is about 

 2J miles long, to | of a mile wide, and rises from 20 to 40 feet above the 

 level of the ocean. It is a barren rock formerly avoided by navigators, and 

 .appears to be entirely composed of the rich phosphatic mineral. Analyses of 

 the substance, by competent chemists, indicate it to bear a resemblance in 

 composition to bones deprived of their cartilage, and otherwise altered, as we 

 might suppose bones to be, exposed to the influence of the ocean water. It 

 contains about the same proportion of phosphate of lime as calcined bones ; 

 and it is this circumstance which has directed the attention of enterprising 

 merchants and agriculturalists to its value as a manure. 



When we recollect that the cereal grains, buckwheat, clover and other legu- 

 minous seeds yield in their ash from 30 to 50 per cent, of phosphoric acid, we 

 cannot but feel the conviction that the Sombrero substance, with its 75 per cent, 

 of phosphates, must prove to be of far more permanent value than the true 

 guano. From this, the Sombrero material deserves to be distinguished by a 

 new name, and perhaps the easy one of O s i t e , from its resemblance in 

 composition to bones and its probable origin, would not be inappropriate. But 

 are we to ascribe the immense mass forming the Sombrero rock to animal 

 origin ? Many reefs and shores of vast extent are known positively to have 

 had their origin in the testaceous coverings of the lower animals, but Som- 

 brero appears to be the first instance of an extensive island formed alone of the 

 remains of the higher animals. The composition of the Sombrero substance, 

 with its included bones, leads us to suspect that the island was once a shoal 

 swarming with turtles and other vertebral animals, whose accumulated re- 

 mains of ages have been cemented together, and gradually elevated above the 

 ocean level to the present position of the island. 



Mr. Hanson informs us that no animals inhabit the latter, independently of 

 birds, except a lizard, about one foot in length, specimens of which he has 

 promised to obtain for the Academy. 



Dr. Leidy further remarked that the bear skull presented this evening by Mr. 

 W. D. Moore, of Oxford, Mississippi, had been found, in association with two 

 portions of jaws with teeth of the Mastodon, in the drift of Claiborne Co., 

 Mississippi. The skull does not differ from that of the common black bear, 

 Ursus Americanus. It is the fourth instance in which Dr. L. has no- 

 ticed the occurrence of remains apparently of this species in association with 

 those of Mastodon, Megalonyx, and other extinct animals. 



1859.] 



