524 GEOLOGICAL SURVEY OF NEW JERSEY. 



narrow, forked " and with a square blotch or a bar of white near 

 the end. Length, 9| inches ; tail, 5 inches. 



" Migratory. Moderately abundant throughout the State. 

 Sociable in their habits, when on the wing, flying frequently low 

 down through the streets of our towns. Semi-nocturnal. Their 

 food consists exclusively of insects. Strictly inoffensive." 



Family CYPSELIDJE. 



(Micropodidse.) 

 Swifts. 



CENTURA, Steph. 



C. pelagica, L. Chimney Swallow, or Swift. 



Sooty brown ; throat paler. Length, 5 inches ; tail, 2 inches. 



" Abundant. Arrive early in April, remaining until late in 

 October. Their nests, as is well known, are generally in chim- 

 neys. Not unfrequently they are in hollow trees, even near a 

 town. They raise three broods generally. Their food is exclu- 

 sively of insects. Strictly inoffensive." 



Family TROCHILIDJE. 



Humming Birds. 



TROCHILUS, L. 



T. colubris, L. Ruby-throated Humming Bird. 



Bill long; tongue capable of great protrusion; wings long 

 and pointed, the secondaries short, only six in number ; rectrices 

 ten ; feet very small, with sharp claws ; male, metallic green 

 above, chin velvet black ; a ruby-red gorget ; tail deeply forked. 

 Female without red ; tail double-rounded and variegated (green, 

 white and black). Young male resembles adult female ; young 

 female like young male, but no streaks on throat, and tail more 

 rounded. Length, 3|- inches; tail, 1J inches; bill, f inch. 



