192 SIXTH REPORT — 1836. 



enter North America are accordingly much more abundant to 

 the south of the isthmus of Darien, and o7ie only {cathartes 

 aura) breeds as far north on the coast as Pennsylvania; in the 

 interior this species reaches the 54th degree of latitude, but it 

 is not known to breed there. Of the falconidcs named in our 

 list, twelve range to South America, or have their head-quarters 

 there, and as many have been detected in Mexico, where they are 

 chiefly winter visiters, while the number that breed on the Sas- 

 katchewan is twice as great as in Pennsylvania : only two {pere- 

 grinus and islandiciis), and these are of the typical group, win- 

 ter in the fur-countries. The strigid(s are very partially migra- 

 tory : otus and brachyotus, the only species which quit the 

 fur-countries in winter, are resident all the year in the United 

 States. Five of the North American owls belong also to the 

 South American fauna. 



Insessores, Detitirostres. — With a very few exceptions, con- 

 fined, or nearly so, to the typical genus lanius, all the North Ame- 

 rican laniadee retire in winter to Mexico, the West Indies, or 

 South America, agreeing in this respect with the fly-catching syl- 

 viadce, which they so closely resemble in their manner of taking 

 their prey ; the tyrannulce especially are numerous in Mexico. 

 The merulidfB wholly quit the fur-countries in winter, and all of 

 them extend their migrations to Mexico, the West Indies, or 

 South America, though detachments of some species, as merula 

 niigratoria, crpheus 2)olyglotfas,rufus, andj'elivox remain with- 

 in the United States all the year: South Carolina is stated by the 

 Rev. Mr. Bachman to be the most northerly winter range of 

 the last-mentioned bird. The breeding-range of birds of this 

 genus is very extensive ; eight species perform that function 

 in all parts of the United States, most of them going as high as 

 the Saskatchewan. The merula migratoria is known to breed 

 from North Carolina to the Arctic Sea ; cinclus americanus 

 and orpheus ncevius breed in the higher latitudes only. Mr. 

 Swainson has remarked of the American sylviadce that they 

 have their head-quarters in Mexico, and that while few species 

 migrate towards South America, many go northwards on the 

 approach of summer*. It is true that the Mexican fauna in- 



• The Rev. Air. Bachman, speaking of the neighbourhood of Charlestown, 

 says, " The yellow-crowned warbler {sylvia coronafa) is the only sylvia out of 

 fifty species inhabiting the United States that remains with us in winter ; and 

 even this bird could not find subsistence in that season were it not that it 

 almost changes its nature and lives on the fruit of the candle-berry myrtle 

 {myrlca cerifera). This is also the case with the only fly-catcher that winters 

 in Carolina, viz., the peewee {tyrannula fused), which sometimes fattens on the 

 seeds of the imported tallow-tree {slylingia cerifera). 



