TYRANNIDA, FLYCATCHERS. 167 
Ozs. Several additional species of jays have been ascribed to our country, but 
apparently upon insufficient evidence or erroneous information. 
Suborder CLAMATORES. Non-melodious Passeres. 
As already intimated (p. 70), the essential character of this group, as distin- 
guished from Oscines, is an anatomical one, consisting in the non-deyelopment of a 
singing apparatus; the vocal muscles of the lower larynx (syrinz) being small and 
weak, or else forming simply a large fleshy mass, not separated into particular 
muscles. This character, however, appears subject to some uncertainty of deter- 
mination, and probably does not always correspond with the only external character 
assignable to the group, namely, a certain condition of the tarsal envelope rarely if 
ever seen in the higher Passeres. If the leg of a kinghird, for example, be closely 
examined, it will be seen covered with a row of scutella forming cylindrical plates 
continuously enveloping the tarsus like a segmented scroll, and showing on its 
postero-internal face a deep groove where the edges of the envelope come together ; 
this groove widening into a naked space above, partially filled in behind with a 
row of small plates. With some minor modifications, this condition marks the 
clamatorial birds, and is something tangibly different from the ordinary oscine 
character of the tarsus, which consists in the presence on the sides of entire 
corneous Jaminze meeting behind in a sharp ridge; and even when, as in the 
case of Hremophila and Ampelis, there is extensive subdivision of the laminz 
on the sides or behind, the arrangement does not exactly answer to the above 
description. The Clamatores represent the lowest Passeres, approaching the large 
order Picarie (see beyond) in the steps by which they recede from Oscines, yet well 
separated from the Picarian birds. The families composing the suborder, as 
commonly received, are few in number; only one of them is represented in North 
America, north of Mexico. 
Family TYRANNIDA. Flycatchers. 
While haying a close general resemblance to some of the foregoing insectivorous 
Passeres, the North American representatives of this family will be instantly distin- 
guished by the above-described condition of the tarsus; and from the birds of 
the following order by the Passerine characters of twelve rectrices, greater wing 
coyerts not more than half as long as the secondaries, and hind claw not smaller 
than the middle claw. 
This family is peculiar to America; it is one of the most extensive and character- 
istic groups of its grade in the New World, the Tanagride and T'rochilide alone 
approaching it in these respects. There are over four hundred current species, 
distributed among about a hundred genera and subgenera. As well as I can 
judge at present, at least two-thirds of the species are valid, or very strongly 
marked geographical races, the remainder, being about equally divided between 
slight varieties and mere synonyms. Only a small fragment of the family is repre- 
sented within our limits, giving but a vague idea of the numerous and singularly 
diversified forms abounding in tropical America. Some of these grade so closely 
toward other families, that a strict definition of the Tyrannide becomes extremely 
difficult ; and I am not prepared to offer a satisfactory diagnosis of the whole group. 
Our species, however, are closely related to each other, and may readily be defined 
in a manner answering the requirements of the present volume. With a possible 
exception, not necessary to insist upon in this connection, they belong to the 
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