François Péron. These appeared in 1809 and 1810 in French scientific serials and deal with jelly-fishes and some other marine animals. Le Sueur was joint author with Anselme G. Desmarest of two papers on certain mollusks and sea-mosses in 1814 and 1815. The papers of which he was sole author number forty-three. They begin in 1813 with a memoir on several new species of mollusks and radiates, published in the Journal de Physique. The first six were written before he came to America, and he picked up material for the seventh on his way over. It deals with three new slug-like mollusks, and is entitled Characters of a New Genus (Firoloida) and Descriptions of Three New Species upon which it is Formed; Discovered in the Atlantic Ocean, in the Months of March and April, 1816, lat. 22º 9’. It appeared in Volume I of the Journal of the Academy of Natural Sciences of Philadelphia, in 1817. Dr. Ruschenberger relates, in his Notice of the Academy, that in the first year of the Journal, "Mr. Ord, anxious to forward the publication, translated or rather prepared the papers of M. Le Sueur from materials furnished by him, as that gentleman, who immigrated from France in 1816, possessed very little knowledge of the English language." The last three of the list appeared in Paris in 1827, 1831, and 1839 respectively. Two are on certain tortoises, the other is an observation on a bite of a viper. Three other papers, written while he was in this country, were published in Paris; the rest appeared in the Journal of the Philadelphia Academy, except one in the Transactions of the American Philosophical Society. He evidently restricted himself quite closely to the fishes and other aquatic animals, though with an occasional excursion among the reptiles.
His descriptions are clear, exact, and honest. His drawings are not accurate only, but spirited. They are works of art rather than mechanical representations. With less range of learning than Rafinesque and some other contemporaries, Le Sueur had, what Rafinesque had not, sound sense and faithfulness in the study of details. In America he was perhaps the first of that school of systematic zoölogy which regards no fact as so unimportant that it need not be correctly ascertained and stated—a method of work with which has been rightly associated the name of Prof. Spencer F. Baird. This attention to accuracy in detail marks the so-called "Bairdian epoch" in vertebrate zoölogy.
The pressure of other duties has led me to abandon the gathering of materials for the study of the lives of the earlier American naturalists. I therefore leave this sketch unfinished, using it
- In the hope that this sketch may some time be completed, I ask any one having additional information regarding Le Sueur's history or his personality to send it either to the editor of The Popular Science Monthly or to the writer.