240 SYSTEMATIC SYNOPSIS.— PASSERES— OSCINES. 
In such eases there are also ten fully developaePrimnarics, the first of which, if not equalling o 
being itself the longest, is at least two-thirds as long. (See p. 428, fig. 279.) 
These combinations of characters may be contrasted for the purpose of dividing the great 
group Passeres into two sections, conventionally denominated sub-orders. 
1. SuBoRDER PASSERES ACROMYODI, OR OSCINES: Sryeine Birps. 
Syrinx with four or five distinct pairs of intrinsic muscles, inserted at the ends of the three 
upper bronchial half-rings, representing the acromyodian type of voice-organ, and constituting 
a highly complex and effective musical apparatus. Side of tarsus covered with a horny plate 
meeting its fellow in a sharp ridge behind; front of tarsus also sometimes laminate. Prima- 
ries ten, with the first short or spurious, or apparently only nine. 
Here belong all the North American families of Passeres, with the single exception of the 
Tyrannide, or Flycatchers, which are clamatorial (mesomyodian). The only North American 
exceptions to the diagnosis given are afforded by the Alaudide, or Larks, and certain Troglo- 
dytide, which, with an oscine syrinx and wing-structure, do not have a bilaminate tarsus. Of 
our 394 Passerine species, no fewer than 363 are Oscine. The name is the Lat. os!cen, in nu. 
pl. os'cines, divining-birds — those whose notes were regarded as augural. 
It is a question, which one of the numerous Oscine families should be placed at the head 
of the series. Largely, perhaps, through the influence of those ornithologists who hold that 
fusion of the tarsal envelope into one continuous plate indicates the acme of bird-structure, the 
place of honor has of late been usually assigned to the thrushes. But only a part of the 
thrushes themselves show this character ; on which account, probably, the rest were associated 
by Cabanis with the wrens. It seems to me most probable that this character, though unques- 
tionably of high import, should be taken as of less value than the reduction of the number of 
primaries from ten to nine ; and I am at present inclined to believe that eventually some Oscine 
family with only nine primaries — as the finches or tanagers— will take the leading position. 
Here, however, I follow usage in the sequence of the North American families of Oscines, as 
follows : — Turdide, Chameide, Parida, Sittide, Certhude, Troglodytide, Alaudide, Mota- 
cillide, Sylvicolide, Tanagride, Hirundinide, Ampelhide, Vireonide, Laniide, Fringillide, 
Icteride, Corvide, Sturnide. 
1. Family TURDIDA:: Thrushes, etc. 
a Be a The essential character of this great group of 
Oscines is, booted tarsi and ten primaries, the 1st 
spurious. But such expression requires qualification, 
for the Turdide do not show this combination with- 
out exception, and birds of some other families do 
possess it. Though it be as natural as any other 
Oscine family of equal extent and variety, and equally 
. ™ close relationships with other groups, it is in the 
nature of the ease insusceptible of perfect definition 
in concise terms. The North American representa- 
tives, however, may readily be circumscribed in a man- 
ner enabling the student to assure himself of the family 
to which they belong. Besides the true Thrushes, the 
Tae Theasies etoeean Redwing family as at present constituted includes the Mocking 
(Turdus iliacus) and Fieldfare (T. pilaris). Thrushes, Dippers, Blue-birds, Kinglets and Gnat- 
ra catchers, with stray representatives of certain Old 
World forms. the Chats and Sylvines, sometimes held to represent separate families (Saxico- 
up! tally 4 \ 
