178 



AVES. 



Fig;. 86.— Sternum of Haw Grosbeak. 



ribs ; the single deep and angular posterior emargination, reduced to a foramen in some ; the 



long, slender, and curving furcula, with invariably a compressed vertical appendage; — all are 



characters that at once indicate the 

 present order, and exclude every 

 one of the genera that have been 

 enumerated. 



They have constantly a large brain, 

 and characteristic form of skull, ex- 

 cepting in one genus* ; twelve tail- 

 feathers, another character which 

 excludes the genera Cypselus, Capri- 

 M mulgus, Podargus, CoUus, Upupa, 

 Trochilus, and Buceros j and their 

 clothing feathers have rarely any 

 trace of the supplementary plume, 

 which is never developed beyond a 

 few downy filaments. All of them are 



hatched naked, and in nearly every instance from coloured or speckled eggs, larger at one end, 



and in a nest constructed and generally interwoven by the parents, — extremely few other 



Birds doing more than heaping together a quantity of materials. 

 The toes are formed for perching ; and ^re always three before and one hindward, the 



outward and middle toes being in every instance connected to the first joint, and sometimes 



further.] 



Tlie first family of this division is that of 



The Dentirostres, — 

 Wherein the upper mandible is notched on each side toward the point.f It is in this famdy 

 that the greatest number of insectivorous Birds occur ; though many of them feed likewise 

 on berries and other soft fruits. 



The genera are determined by the general form of the beak, which is stout and compressed 

 in the Shrikes and Thrushes, flattened in the Flycatchers, round and thick in the Tanagers, 

 and slender and pointed in the Pettychaps group ; but the transitions from one to another of 

 these forms are so gradual that it is very difficult to limit the genera. 



[The study of the changes of plumage, and even colours and markings, aff"ords considerable 

 assistance in determining the affinities of the various genera, — more so, perhaps, than any 

 other character.] 



The Shrikes (Lanius, Lin.) — 



Have a conical or compressed beak, more or less hooked at the point. 



The Shrikes, properly so called, (Lanius, Vieillot) — 

 Have it triangular at the base, with compressed sides. They live in families [for a few weeks after the 

 breeding season], fly irregularly and precipitately, uttering shrill cries ; nestle on trees [or in bushes] ; 

 lay five or six eggs, and take great care of their young. They have the habit of imitating, in the wild 

 state, part of the songs of such Birds as live in their vicinity. The females [?] and young are gene- 

 rally marked with fine transverse lines on the upper parts. 



Some have the upper mandible arched ; those in which its point is strong and much hooked, and in 

 which the notch forms a small tooth on each side, manifest a degree of courage and cruelty which has 

 led to their association with the Birds of Prey by many naturalists. In fact, they pursue other Birds, 

 and successfully defend themselves against the larger ones, even attacking the latter whenever they 

 intrude in the vicinity of their nest. 



; the liifferent spe 



nf whicli are singularly 



I -f No trace of this notcli i 

 I " tooth" of certain Acdpitr 



r visible in tlie bone, from which the 

 I true process — Eu. 



