456 SYSTEMATIC SYNOPSIS. — PICAMI^ — CYPSELIFOBMES. 
widening behind, its posterior margin entire; furcaluni stout, rather U- than V-shaped. Oil- 
gland nude. No coeca. Leg-muscles anomalogonatous (p. 195) ; femoro-caudal present, but 
accessory femoro-caudal, semitendinosus, accessory semitendinosus and ambiens absent. Eggs 
several, narrowly oval, white. 
One of the most remarkable points in the structure of the Cypselidce is the great devel- 
opment of the salivary glands. In all the species of which the nidification is known, the 
secretion thus produced is used more or less in the construction of the nest. In most cases it 
forms a glue by which the other materials are joined together, and the whole nest is affixed to a 
rock, wall, or other object against which it is placed. In some species of Collocalia, however, 
the whole nest is made up of inspissated saliva, and becomes the ' edible bird's nest ' so well 
known in the East." (Sclater.) 
A well-defined family of 0 or 8 genera and about 50 species, inhabiting temperate and warm 
parts of the globe. Thdy are rather small birds, of plain plumage, closely resembling swallows 
in superficial respects, but with no real affinity to these Oscines. Notwithstanding the utmost 
difference in the shape of the bill, the real affinities are with the tenuirostral Trochilidce in 
every structural peculiarity. They are birds of extraordinary volitorial ability, being only sur- 
passed in this respect by the hummers themselves. The family is divisible into two subfami- 
lies, according to the structure of the feet. 
Analysis of Stibfamilies and Genera. 
Cypselin^. Front toes with 3 joints apiece. Hind toe lateral or versatile. Tarsi feathered. 
Toes feathered. Tail not spiny Panyptila 131 
Ch^turin^. Front toes with 3, 4, and 5 joints from inner to outer. Hind toe posterior or lateral, but 
not reversed. Tarsi and toes naked. 
Tail emarginate, not mucronate Nephoecetes 132 
Tail rounded, mucronate Chcetura 133 
31. Subfamily CYPSELIN>E: Typical Swifts. 
Eatio of the phalanges abnormal, the 3d and 4th toes having each 3 joints like the 2d ; 
basal phalanges of all the anterior toes very short (fig. 40). Hind toe reversed (in Cypselus, 
where nearly all the species belong), or lateral (in Panyptila). Tarsi feathered (in Cypselus) ; 
toes also feathered (in Panyptila). Contains only these two genera and nearly half the species 
of the family. Of Panyptila there are only three well-determined species, all American ; while 
Cypselus has upward of twenty, mostly of the Old World ] the three or four American ones 
being sometimes detached under the name of Tachornis. 
131c PANY'PTILA. (Gr. ndvv, panu, much, very; tttIXov, ptilon, wing : in allusion to the length 
of wing.) EocK Swifts. Tail about i as long as wing, forked, with stiffish and narrowed, 
but not spiny feathers. Wing pointed by the 2d primary, the 1st decidedly shorter. Tarsi 
feathered to the toes ; these also feathered to some extent. Hind toe elevated, lateral, but not 
reversible. Front toes with slight basal webs. Eyelids naked. Colors black and white. 
403. P. saxa'tilis. (Lat. saxatilis, rock - inhabiting ; saxum, a rock.) White-throated Eock 
Swift. Black or blackish ; chin, throat, breast, and middle line of belly, tips of secondaries, 
edge of outer primary and lateral tail-feathers, and a flank-patch, white. Forehead and line 
over eye pale ; a velvety black space before eye. Bill black ; feet drying yellowish. The 
purity of the color varies with the wear of the feathers, some specimens being dull sooty 
brownish, others more purely and even glossy blackish. The extent of the w^hite along the 
belly is very variable. The flank-patches are conspicuous, in life sometimes almost meeting 
over the rump. Length 6.50-7-00; extent about 14.00 : wing the same as total length; tail 
about 2.66, forked, soft. Southwestern U. S. and southward, breeding in colonies on cliffs ; a 
large and beautiful smft — a high-flier of almost incredible velocity, with a loud shrill twitter, 
nesting in the most inaccessible places, sometimes by thousands. The eggs do not appear to 
have been taken yet, but are presumed to be white, as in all the species the eggs of which are 
known. Found N. to Wyoming, Utah, and Nevada. 
