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 Dicruridte 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 artificial 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 insuflficient 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 

 character they have in common with the Crows. In some 

 all the plumage is burnished with metallic reflections, in others 

 partly so. A few wear an ashy-coloured dress, with more 

 or less of a silky gloss ; and in four of the species pure white 

 enters into the mature coloration. Specific differences are 

 therefore not easily to be established by slight variations in 

 colour ; and structure becomes the most available guide. The 



