NATURAL SCIENCES OF PHILADELPHIA. 121 



ises que ne sont ni de vraies plantes, ni de vrais anitnaux. Ce n'est qu'a. 

 force d'observations et de meditations que l'on pourra distinguer clairement 

 les vraies plantes et les vrais animaux des autres etres organises qui en different 

 assez pour avoir une autre determination et uu autre rang dans la division 

 methodique des productions de la nature." (Seances des Ecoles Normales, 

 tome v. p. 277.) 



We cite these authors only for the general purpose of illustrating the usual 

 style of the suggestions and opinions frequently to be met with. Purposely, 

 at present, we do not extend extracts of this description, nor give any such 

 from living authors. 



On the LESTRIS RICHARDSON/I of Swainson ; with a Critical Review of the 



Subfamily LESTRIDINJE. 



BY ELLIOTT COUES, M.D., U.S.A. 



In the year 1831, a Jager was described and figured in the Fauna Boreali- 

 Americana, under the name of " Lestris Richardsoni Swains." This bird has 

 been generally supposed to be the true parasitica of Briinnich, in the now 

 well known fusco-unicolor state of plumage which all the species of Stercora- 

 rius pass through in arriving at maturity. Consequently, the name "Richard- 

 soni " has been employed for the common Jager, especially by American 

 writers, to the exclusion of the prior name "parasitica," of Briinnich. 



Examination of the works of Temminck, who, at the time in which he 

 wrote, probably knew more about Jagers than almost any author, will show 

 how this misapplication of a name became general. 



In his edition of 1820, he is acquainted with but a single species of Lestris, 

 (besides catarractes and pomarinus,) which he calls "parasitica Briinn." His 

 description of the latter is made up of a mixture of the characters of parasitica 

 and Buffoni ; and the synonyms of the two are indiscriminately adduced. 



In his edition of 1840, he recognizes the distinctions between the two 

 species parasitica and Buffoni; but, unfortunately, he calls the true parasitica 

 "Richardsoni," adducing the proper synonyms of the species under that 

 name ; while he describes the true Buffoni under the name of "parasitica.'" 

 He is thus fully aware of his mistake of 1820 ; for (page 498) he makes the 

 following "Remarque : Comme notre article du stercoraire parasite oulabbe 

 du manuel p. 796, renferme, ainsi qu'il vient d'etre dit, les synonymes de deux 

 especes distiuctes, (le stercoraire a filets subules courts, et le stercoraire a 

 longs filets,) il est necessaire de refaire en totalite toutes les indications sur ces 

 deux especes." 



But, believing Swainson's bird to be the same as the parasitica, he says 

 (page 492), in defence of the nomenclature adopted: "Shortly after the 

 publication of the second edition of the Manual, of 1820, we became aware of 

 the error in our article on Lestris parasitica, where the description and 

 synonymy of two distinct species are confounded. Guided by Boie's observa- 

 tions, we had applied the name parasitica to the small Jager with short tail 

 feathers, proposing to adopt for the one with long tail feathers (the labbe a 

 longe queue of Buffon,) the name Buffoni ; but since some English authors,* 

 led into error by our article, have thought that they have discovered in our 

 parasitica & new species, which they call " Richardsoni," we are obliged to 

 adopt their mistake, sanctioned as it is by several naturalists, and in many 

 collections. Being, then, confident that Lestris Richardsoni is really the same 

 with our L. parasitica, with short tail feathers, . . . we adopt here the 

 first of these names for the short-tailed Jager, leaving to the long-tailed species 



* i. e., Swainson, and others. 



1863.] 



