70 
The Marquis of Tweeddale on the 
rapid while it lasts. Most writers_, and certainly all those who 
have observed members of this family in a wild state, must 
agree with Jerdon in classing the Dicrurid(B between the 
Shrikes and the Flycatchers; and I venture the opinion that 
it will require a more comprehensive and stronger character 
than that of the relative position of the nares and the chin- 
angle before ornithologists will concur in associating them 
with the Crows and the Orioles. 
It is not proposed in the following notes to debate whether 
the Coliomorphse of Mr. Sharpe constitute a natural or an 
unnatural and highly artihcial group. Their object is rather 
to notice a few errors which it seems desirable in the interest 
of science to correct before they pass into general circu¬ 
lation, and before they become adopted, as they naturally will 
be, by authors influenced by the high authority of the 
work in which they appear. This volume of the Catalogue 
of Birds, as well as the two it follows, deserves our acknow¬ 
ledgment ; and whether we approve or disapprove of the clas- 
sificatory system adopted, we cannot withhold the expression 
of our satisfaction at the diligence it discloses. If there are in 
it important omissions, occasional errors, and evidences of a 
desire to create new species on grounds less valid than those 
considered by the author insufficient to support the species of 
others, it is certainly more owing to lack of leisure than to a 
disinclination to labour. The systematic arrangement of the 
species by Mr. Sharpe seems in some cases artificial, and not 
always to be unlocked by the key he supplies for the genera. 
There is also a certain inconsistency displayed in the discri¬ 
mination of the species; but it must be acknowledged that 
some of these are exceedingly difficult to make out. .■ 
The prevailing colour of the Dicruridse is black—the only I 
character they have in common with the Crows. In some M 
all the plumage is burnished with metallic reflections, in others H 
partly so. A few wear an ashy-coloured dress, with more m 
or less of a silky gloss; and in four of the species pure white 11 
enters into the mature coloration. Specific differences are HI 
therefore not easily to be established by slight variations in ■: 
colour; and structure becomes the most available guide. The 
