148 GENERAL ORNITHOLOGY part ii 



in the same manner and for the same purposes as the lips and teeth 

 of man or other vertebrate animals. All bills, thus similarly consti- 

 tuted, have been divided by the author into 



Foup Classes, representing as many Avays in which the two 

 mandibles close upon each other at the end. 1. The epignathoiis 

 (Gr. e-t, e])i, upon, yra^o?, gnathos, jaw) way, plan, or type, in which 

 the upper mandible is longer than the under, and its tip is evidently 

 bent down over the tip of the lower. 2. The hypognathous (Gr. 

 ii?ro, Impo, under), in which the lower mandible is longer than the 

 other. 3. The paragnathous (Gr. Trapd, pxira, at or by), in which 

 both are of about equal length, and neither is evidently bent over 

 the other. 4. The metagaathous (Gr. ij-erd, meta, with, beside, etc.), 

 in which the points of the mandibles cross each other. The second 

 and fourth of these are extremely rare ; they are exemplified, re- 

 spectively, by the skimmer and the crossbill (genera Bhynchopjs and 

 Loxia). The first is common, occurring throughout the birds of 

 prey, the parrots, and among the petrels, gulls, etc. etc. The great 

 majority of birds exhibit the third ; and, among them, there is such 

 evident gradation into epignathism, that it is necessary to restrict 

 the latter to its complete development, exhibited in the intermax- 

 illary bone divested of its horny sheath, which often, as among 

 flycatchers, etc., forms a little overhanging point, but does not 

 constitute epignathism. These classes, it should be added, though 

 always applicable, and very convenient in descriptions, are purely 

 arbitrary, that is, they by no means correspond to any four large 

 groups of birds ; but, on the contrary, usually only mark families 

 and the subdivisions of families ; and the four types may be seen 

 in closely related genera. The general shape of the bill has also 

 furnished 



Other Classes, for many years used as a large basis for orni- 

 thological classification, even for the establishment of orders ; but 

 which the progress of the science has shown to be merely as con- 

 venient as, and only less arbitrary than, the foregoing. The principal 

 of these are rejiresented by the following types : A, among land 

 birds. 1. The fissirostral (Lat. fissus, cleft, and rostrum), or cleft, 

 in which the bill is small, short, and with a very large gape running 

 down the side of the head ; as in the swallow, chimney-swift, goat- 

 sucker. 2. The tcnuirostral (Lat. tenuis, slender), or slender, in 

 which the bill is narrow, long, and with a short cleft ; as in the 

 humming-bird, creeper, nuthatch. 3. The dentirostral (Lat. dens, a 

 tooth), or toothed, in which, with a various general shape, there is 

 present a nick, tooth, or evident lobe in the apposed edges of one 

 or both mandibles near the end ; as in the shrike and some wrens, 

 thrushes, and waiblers. 4. The conirostral (Lat. coiius, a cone), or 

 conical, sufficiently defined by its name, and illustrated by the great 



