SWALLOWS. 507 



answer each other from various parts of the tliickets. They have a variety of ot]>er 

 notes rcseiiiMing tliose of tliu wrens, and corres])ond with them also in most of their 

 habits, hunting their insect j)rey in tlic vicinity of the ground or on low trees, often 

 holding their tails erect, and usually so shy that they can only be seen by patient 

 watching, when curiosity often brings them within a few feet of a person ; and, 

 as long as he sits quiet, they will fearlessly hop around him as if fascinated." 



The mocking-birds (Jlniin.E) arc hardly entitled to family rank independent of 

 the Troffloilytid.'e, from which they chiefly differ in having wcll-develoj)ed bristles at 

 the mouth, and in being on an average somewhat larger, though the smaller mocking- 

 birds arc not so large as the largest wrens. Like all the birds of the jaresent group 

 they are eminently American, and seem to have the centre of their distribution in 

 Central America, the West Indian Islands, and the southwestern United States. 

 The mocking-l)ird (J/i>in(.f po/i/(/lo/tiis), the rival of the nightingale for the 'cham- 

 pionship of the world' as a songster, the cat-bird {Galeoscoptes carolinensis), and 

 the brown thrasher { Ilarpor/ii//ii/ii/s n/f/is) are representative birds of this family, 

 and their song and habits too familiar to American readers to require further notice 

 in this connection. 



Whether the place here assigned to the Polioptilinjc, or gnat-catchers, is correct 

 may pcrhajis be (luestioned, but I think it safe to say that its position with the Mimidae 

 is more satisfactory than either with the Sylviida?, Parida?, or Mniotiltidas. Indeed, I 

 see little to separate them from the mocking-birds except the slightly more depressed 

 bill and the size, the gnat-catcher belonging to the smallest of passerine birds. Musci- 

 capine relationship has been suggested, but the form and ])osition of the nostrils 

 opposes such a view, as does also the geographical distribution, Polioptila being 

 exclusively American, and the Muscicapida; exclusively Old "World forms. However, 

 I may (piotc what Mr. IJ. B. Shar]ie says about the question : — 



"I believe that the most natural position for the genus will be in the vicinity of 

 the muscicapine genus Stenostira, to which, both in form and style of coloration, 

 Polioptila liears a striking resemblance, as has already been pointed out by Bonaparte, 

 Sclater, and other ornithologists. Shouhl this classification turn out to be correct, it 

 will afford another instance of the affinity of the avifauna of North America with 

 that of South Africa, as alrculy noticed in the occurrence of Pelrochelidon spilodera 

 at the Ca]H', a close ally of 1'. 2)y)'rho)wta [/•". luiiifrons] of North America." I may 

 here remark, that the swallow genus Petrochelidon is found both in South America, 

 Australia, India, and South Africa; that the swallows are very uniform both in form 

 and coloration all over the world; that they are the fastest travelers of all jiasserine 

 birds; consequently the similarity between the American and the African species is 

 not so extemely surprising. On the other liand, the true fly-catchers arc very poly- 

 morphic, and the distribution of the gnat-catchers and the Stenostira so disconnected 

 that I prefer to regard the former as nearly rdateil to their comitrymen, the mocking- 

 birds, es])ecially as character of structure or coloration seems to make such a view 

 untenable. The habits do not point either way, so far as I know. The gnat-catchers, 

 a little over a dozen s])ecics, belonging to one gcmis oidy, inhabit all parts of America 

 except the most southern ami most northern portions. 



Contrary to the general run of passeroid families, that of the sw.allows, the Ilinrx- 

 DiNin.K, is as well defined and isolated ,as any of the ])icarian families, at least exter- 

 nally. They are possessed of extremely long and pointed wings, with nine jirimaries ; 

 the feet are reduced very much in size ; the bill is short but extremely broad, and the 



