40 ZOOLOGICAL LITERATURE. 
Hitchcock, C. Description of a new Reptilian Bird [Tarso^ 
dactylus expansus] from the Trias of Massachusetts. Ann. 
Lye. New York, 1866, pp. 301-302. 
Lilljeborg, W. Outlines of a Systematic Review of the Class 
of Birds. Proc. Zool. Soc. 1866, pp. 5-20. 
The author first gives a concise sketch of the Literature of 
the subject, and then passes to the Principles.'’^ Irritability’^ 
seems to him to be the most distinguishing character for birds, 
and to be possessed in the highest degree by the Passeres. He 
does not mean by irritability muscular strength alone, but viva- 
city and activity generally. The birds of prey, though generally 
placed highest, are in reality far behind the Passeres, The 
former also correspond Avith the lower groups of Columbine and 
Gallinaceous birds, outwardly as regards the nature of their 
wing-coverts, and inwardly as regards their carotides communes. 
A system that places the dirty Vultures highest does not seem 
to us to indicate a correct idea of the nature of birds.” 
[We have here indicated, so far as Ave are able to understand 
them, Avhat the author terms his Principles ” of Classification. 
Of the rest of his remarks on the subject we must confess our in- 
ability to see the drift. The character of Irritability ” is not 
again invoked, being j)erhaps left for a critic to show ; nor is any 
hint given how it may be measured or its different degrees defined. 
We must therefore beg our readers who are curious in the matter 
of systematic classification to consult Prof. Lilljeborg’s paper 
and judge for themselves ; Ave can here only append a brief out- 
line of its results.] 
Prof. Lilljeborg divides the class Aves into three subclasses : 
(I.) Natatores, (II.) Cursores, and (III.) Insessores. The first 
of these forms two sections : — (i.) Bimplicirostres , containing 
three orders, (I) Pygopodes, (2) LongipenneSy and (3) Stegano- 
podes, and {^\.)Lamellirostres, consisting of a single order (4) of 
the same name. The second subclass is composed of three 
orders ; — (5) Grallce, (6) Brevipennes, and (7) Gallmce. The 
third contains five orders (8) PullastrcBy (9) Accipitres, (10) 
Strisores, (11) Zygodactyli, and (12) Passeres. These tAvelve 
orders are subdivided into fifty-nine families and 144 \ sub- 
families. 
Reprinted (in Report of Smithsonian Institution ?) at Washing- 
ton, with the characters translated from Latin into English by 
Professor Gill. 8vo, pp. 436-450. 
Millet, C. Etudes sur les oiseaux voyageurs et migrateurs et 
sur les moyens de les proteger. Bull. Soc. Imp. d’Acclimat. 
1866, pp. 272-282. 
A scheme is proposed for marking migrant birds by differently coloured 
threads, whereby their movements may be more certainly determined j and 
international protection of these species is recommended. 
