TROCHILIDyE : HUMMINGBIRDS. 543 



as in placing the yoke-toed (vvliether heterodactylous or zygodactylous) families together, after 

 the anisodactylous or pamprodactylous ones ; it heads the list with the Humuiers, and foots it 

 with the Cuckoos ; and it violates no obvious interrelations of the intermediate famihes. Hav- 

 ing these recommendations, this is the sequence I shall adopt in the present edition of the 

 Key.* 



Suborder TROCHILI : Hummingbirds. 



See p. 540 for analytical characters of this group, especially in comparison with the tissi- 

 rostral macrochirous type — the Ci/jiseli. The skeleton agrees closely, iu general, with that 

 of the Swifts, but has many minor peculiarities in detail, among which the most prominent are 

 the modifications of the facial bones conformably with the long slender bill. The palatal ar- 

 rangement is schizognathous. The deeply carinate sternum widens toward its uunotched 

 xiphoid border; there is no manubrium; the furculum is U-shaped, with rudimentary hypo- 

 clidium ; the coracoid canaliculate; the humerus very short and stout, the radius arched, the 

 metacarpus and phalanges greatly elongated. A chief anatomical peculiarity is the structure 

 of the tongue, which somewhat resembles a Woodpeckei-'s in being protrusible or capable of 

 being thrust far out of the beak by a muscular mechanism connected with the long horns of 

 the hyoid or tongue-bone, which curve up around the back of the skull ; the tongue is in efl'cct 

 a sheathed double-barrelled tube, appearing like two cylinders united for some distance, tlien 

 opening out with a thin lacerated edge. This structure is supposed to be used to suck the 

 sweets of flowers. There are no cseca, and the oil-gland is nude. The myological formula lacivs 

 the ambiens, accessory femorocaudal, semitendinosus, and its accessory, as in the Swifts ; the 

 flexor longus hallucis supplies the hallux and by a branch the second digit, besides sending the 

 remnants of slii)s to the third and fourth ; the second, third, and fourth digits are supplied as 

 usual by the flexor digitorum. There are no sterno-tracheals. There is one carotid artery, the 

 left. The pterylosis is characteristic. This is a highly monomorphic or monotypic group, 

 containing a single definitely circumscribed family, peculiar to America, and specially charac- 

 teristic of the Neotropical region. 



Family TROCHILID^ : Hummingbirds. 



Tenunostral macrochirous Picaricc. These beautiful little creatures will be known on 

 sight by their diminutive size and gorgeous coloration, without regard to their technical char- 

 acters. They are called Hummingbirds because their wings make such a noise in flight, 

 whirring so rapidly that the eye cannot follow their vibrations. The French know them as 

 oiseaux-mouches, or "bird-flies," for the same reason; their curious resemblance to insects has 

 struck every one who ever saw a Hummer pcnsed on misty pinions before a flower, when a 

 second glance might be refpiired to distinguish the feathered bird from a furred sphinx-moth. In 

 ])owers of flight the Hummers are equalled by few if any birds, and certainly surpassed by none 

 iu the marvellous rapidity with which they dart through the sunsiiiue. ^ 



• The arranRement in former editions of the Key is: Ctpseliformes, Caprimiilffidir, Ci/psrlidir, Trochilidcr ; 

 CucuLiFORMEs, Troffoniilip, Alreiliiiklir, Cuciilktif ; Picifokmes, I'irkia-. This is bad, both in the construction of sub- 

 orders and sequence of families. In the classification atlopted in tlie A. O. U. Lists there is some faulty construction of 

 three major groups as in Key, with an improvement in their sequence. Reversing the A. O. U. arrangement, which pro- 

 ceeds from lowest to highest, in order to correctly exhibit its relations with the foregoing, we find it to be : Order Macro- 

 CHtREs ; Suborder Trix hili, Troc/iilitftr ; Suborder Cypseli, Afitropoilidir ; Suborder Caprimuloi, Caprimiilgitlir. Order 

 Pici ; no suborder, /'Iriilir. Order Coccyges ; Suborder Alcyones. Alcedini<l(r : Sahorder Trooones, Trogonuiir ; Sub- 

 order CucuLi, Ciiruliilir. In the Standard Natural History, Dr. Stejneger judiciously recognizes the seven North Amer- 

 ican superfaniilies of Picarian birds ; but their sequence is less happy, especially in the wiile separation of C(ij>ritiiul(jiit(r 

 from Ciijisilidir and Trm/iilidir His seipience rever.sed, or from highest to lowest, is, for the foregoing families : Tro- 

 chilidir, Miiiiiiiodidrr, Tniiioiiidir, J'icidtr, Alcriliiiidir, Cfipriiniilijiiltr, Cuciilidtr. Both the numl>er and the sequence of 

 groups, so far as those of North America are concerned, as given in the foregoiug text, are identical with those presented 

 iu the British Museum Catalogues. 



