east. This hypothesis was verified in 1852 by Captain McClure's making the passage in the direction described.
As Mr. Lea advanced in his geological studies, he found that it was necessary to know something of shells. In order to study their genera as described by Lamarck, he imported a large collection of shells from China. He soon became interested in this branch of the science, and ultimately made it the leading object of his researches. A collection of several species of Unio, including some beautiful and rare specimens, was sent to the Academy of Natural Sciences, in 1825, by Major Long, of the Engineer Corps, who had obtained them in dredging the channel of the Ohio River below Louisville. At about the same time, Mr. Lea's brother Thomas, having engaged to look after the shells in the vicinity of Cincinnati, where he was living, shipped a barrel of shells of rare beauty, including six new species. The description of these specimens—"Description of Six New Specimens of the Genus Unio"—presented to the American Philosphical Society in 1827, formed the first of that long series of papers on the Unio and allied shells which constitute the chief of Mr. Lea's works. Yet, at the time he presented it, he had no thought that he should ever have another word to say on the subject, for at that time no one conceived the infinite variety of species of the family which American waters are now known to contain. As a side-result of Mr. Lea's interest in the Unios may be mentioned the conversion of his brother from an indifferent barreler of shells for another to an enthusiastic student of land-shells and botany, and to be the author of a monograph on "The Plants of Cincinnati."
Dr. Lea spent the traveling season of 1832 in Europe, where the journal of his excursions is a record of successive introductions to famous scientific men, and interesting conversations with them, in which he was never the only one who received information. In London he attended a meeting of the Geological Society, and met most of the leading geologists of Great Britain. At Oxford, he attended the second meeting of the British Association, over which Dr. Buckland presided. Meeting Dr. Buckland afterward in London, the conversation turned upon the quantity of coal in the United States. Dr. Buckland thought we had very little coal. Dr. Lea pointed out on a map the coal-fields of the United States as they were then known. After several hours spent in the examination of the matter, Dr. Buckland taking notes all the time, the distinguished geologist remarked, as he took his leave to meet an engagement, that England had enough coal to supply the United States when its supply should fail. Dr. Lea replied that the quantity of anthracite and bituminous coal was almost unlimited in North America, and promised to send him maps and sections that would satisfy him upon the subject. He fulfilled his promise after he returned home, and, upon the evidence thus afforded, Dr. Buckland presented a paper to the next meeting of the British Association on the extent of our coal-supply. At the British Museum, by the re-
