MONOGRAPH OF THE NORTH AMERICAN 



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

 interestinK and difficult group. He has already published, in the Proceedinss of tl"® 

 Philadelphia Academy of 1862-'63, revisions of the North American 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 

 offered. 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 have been modified, while a few mistakes in those articles have been corrected ; 

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

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

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



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

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

 policy of the Institution has permitted me to fully avail myself. I have also 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 Jlr. Lawrence. I have aimed to make the present article strong enouyli to bear 

 the term '• monograph." It embraces all the species known to occur in Xorth 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 forgeo- 

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

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

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

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

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

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

 out the slightest personal bias. The matter of geographical distribution 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 cou- 

 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 Xa;-if?iHe birds which have 

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

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

 Huxley unites the Laridw and ProceJlariidw with the Alcidce, <tc., in a group Cecomor- 

 pliw. Eespectiug the Laridw alone, most authors make them a family with either two 

 or four suijfamilies. The genera which have been proposed 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 consideralde 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. Brut"h 

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

 Bruch's work of l.^.jS required in 1855 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, which occurred while the 

 article on Laridw was printing in the " Conspectus," is too well known to require com- 

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

 though some species are rejected which he might have retained had he seen them. Mr. 

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



