MONOGRAPH OF THE NORTH AMERICAN 



Several years have passed since the writer began to pay special attention to this 

 interesting and difficult group. He has already published, in the Proceedings of the 

 Philadelphia Academy of 1862-'63, revisions of the North Aruerican forms of the prin- 

 cipal subfamilies, preliminary to the present more complete work. This memoir has 

 lain in Mss. since 1864, being retouched from time to time, as additional material 

 ofi'ered. Final revision has been made within the present year, bringing the subject 

 up to date. Since the earlier papers were published, my views of what constitutes a 

 species hxve been modified, while a few mistakes in those articles have been corrected ; 

 but I find comparatively little to alter. The article on Larldcv. in the " Key to North 

 American Birds" (1872), expresses very nearly my present views, though one or two 

 hasty stefjs in that portion of the work require to be retraced. 



Containing the richest collection of American LarUhe in the world, the Smithsonian 

 Museum otiers great facilities for this study — facilities of which the liberality of the 

 jjolicy of the Institution has permitted me to fully avail myself. I have al.'iO examined 

 the specimens in other of our large public collections, while many have been furnished 

 me from private sources. For favors of this kind I am particularly indebted to my 

 friend Mr. Lawrence. I have aimed to make the present article strong enough to bear 

 the term " monograph." It embraces all the species known to occur in North America. 

 These are treated in full, with frequent reference to estralimital allies, As will be ob- 

 served, extensive synonymical lists have been prepared, embracing, it is believed, nearly 

 all the names which have been proposed, with many additional references for geo- 

 graphical distribution, &c. Most of the quotations have been personally made or ver- 

 ified ; in cases in which this was impracticable, the authority is generally added. No 

 one need be reminded how difficult it is to get such lists of thousands of figures printed 

 correctly, there being, of course, no guiding context for the compositor. I can only 

 hcpe that, as elsewhere in this volume, references to dates, volumes, pages, and plates, 

 will be found geuerallj' correct. Most points of synonymy are freelv discussed, with- 

 out the slightest personal bias. The matter of geographical distributiou receives 

 special attention. Seasonal changes of plumage, and those dependent on age — great 

 in this family, and frequently perplexing — as well as individual variations in size and 

 coloration, are given in full, so far as I am acquainted with them. The chief anatom- 

 ical peculiarities of the subfamilies and leading genera are presented from original 

 dissections. 



A beautiful series of colored illustrations of the head, wing, and other characteristic 

 parts, prepared for this memoir by a competent artist, will be presented in the con- 

 cluding volume of Prof. Baird's work, now publishing, it being impracticable to print 

 them here. 



It is unnecessary to advert to various classifications of the ZarMne birds which have 

 been proposed and received more or less support. Authors differ even as to the limita- 

 tious of the group, while no two are entirely in accord as to its subdivisions. Prof. 

 Huxley unites the Laridcv and ProceUariidw with the Alcidiv, &c., in a group Cecomor- 

 pha\ Respecting the Laridw alone, most authors make them a family with either two 

 or four subfamilies. The genera which have been proj)osed are altogether too many. 

 There are but four leading genera, corresponding to the four subfamilies; and but 

 few others need or even permit recognition. I subdivided too much in my earlier 

 papers, and now throw most of the so-called genera under Larus and Sterna respect- 

 ively. 



Disclaiming any desire to institute comparisons between this and other memoirs on 

 the subject, a few leading ones may be noticed. One of the earliest special papers of 

 any considerable merit, is Macgillivray's, in the Wernerian Society's :Memoirs; it is 

 very good, as far as it goes. The same cannot be said of certain later articles. Brudi 

 and Bonaparte, it is believed, have been signally unsuccessful in handling these birds. 

 Bruch's work if l>*').\ reipiiied in l!-."j."> altogether too many changes to leave much to 

 be said in its favor; while his later paper itself might be very harshly criticized. The 

 character of Bonaparte's general work just before his death, wliicli oeeurred while the 

 article on l.nriihr was printing in th(< "Conspectus," is too well known to re(|uir(> com- 

 ment. Prof Schlegel's articles in the '• Museum Pays-Bas" are much more satisfactory, 

 though some sjiecies are rejected which he might have retained had he. seen them. MV. 

 Lawrence's contribution to Prof. Baird's work of 1858 is an important advance from 



