548 THE POPULAR SCIENCE MONTHLY. 



Frangois Pdron. 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 mol- 

 lusks and radiates, published in the Journal de Physique. The 

 ^rst 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. 22 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 Philo- 

 sophical 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 zoology which regards no fact as so unim- 

 portant 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 zoology. 



The pressure of other duties has led me to abandon the gather- 

 ing 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 ad- 

 ditional 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. 



