414 Mr. Strickland’s Commentary 
So also the group of the Kestrels was first defined as a genus 
by Boié under the name of Cerchneis; and this term ought, 
I conceive, to be retained rather than Tinnunculus, which is 
merely the name by which Brisson designated the common 
species of Northern Europe. I shall point out other cases of 
the same kind below. 
Before proceeding to details, I wish to make a few further 
suggestions of improvements which might be introduced with 
advantage in future editions of this work. 
1. In the present work the student is unable to judge what 
extent Mr. Gray assigns to each genus, no definitions being 
given, and only one species quoted as an example. In his 
preface, however, Mr. Gray holds out a prospect of publishing 
the characters to his genera, a plan which I trust he will 
execute. At any rate he ought to lose no time in publishing 
the definitions of all the new genera contained in this work, 
it being held by some naturalists that to give a generic name 
without a definition does not constitute an act of publication ; 
and he is thus exposed to the same kind of petty larceny by 
which Vieillot anticipated so many of Cuvier’s genera. For 
the same reason Mr. Gray ought to give names at once to all 
those generic groups which are indicated in the present work 
without being named. 
2. In all cases where the species quoted as the type of a 
genus remains wnfigured, a reference should be made to some 
work in which it is described, otherwise the student has no 
clue to the characters of the genus. 
3. A distinction should be made between those genera 
which are retained exactly as at first defined by their authors, 
and those which have undergone subsequent restriction. Ge- 
nera of the former class may remain with merely the name of 
the author attached, as Jrena, Horsf. Genera which are now 
confined within more restricted bounds than when originally 
defined, may be distinguished by the syllable (s-est.) after the 
author’s name; thus Corvus, L. (restr.), Sphenura, Licht. 
(restr.), &c. 
4. In reciting the synonyms to each genus it would be a 
great improvement to distinguish those terms which are ex- 
actly equal in extent to the adopted genus, from those which 
are either more or less comprehensive. The neatest way of 
expressing this seems to be by means of the algebraic signs 
> greater than, = equal to, and </less than. Thus I would 
write CrypsirRHINA, Vieill., 1816, (restr.), = Temia, Cuv., 
1817, = Phrenothrizx, Horsf., 1821, < Corvus, Lath., < Colius, 
Lath., < Glaucopis,Tem. Again, Conurus, Kuhl, 1820, = 
Aratinga, Spix, 1824, > Psittacara, Vig., < Psitiacus, Shaw, 
