THE GOAT-SUCKER. 
39 
there was a strong twilight, and we have listened in 
vain for the Sky-lark's note, beyond the hour above 
mentioned ; though in the northern part of Scotland, 
and Shetland islands, still further northward, where 
in Summer it is scarcely ever dark, they are heard 
throughout the night singing ; and, again, to use old 
Izaak Waltons words, “ ascending higher into the 
air, and then for a time ending their heavenly em- 
ployment, becoming mute and sad to think they must 
descend to the dull earth, which they would not 
touch, but from necessity." 
TABLE XII. (See vol. i. p. 15.) 
Order 2. Passerine. Tribe 6 . Planirostres. 
This tribe contains but three genera, two of which, 
namely, the Swift and the Swallow, are, by common 
observers, considered as the same, though there is a 
remarkable difference in the position of their claws ; 
the third is that of the Goat-suckers, whose enor- 
mously wide gaping mouths, and short, flat, softish 
beaks, at once distinguish them from other species. 
SCULL OF A GOAT-SUCKER. 
