Additions to the British Fishes. 521 
I consider to be much less plentiful than the yellow wren, 
though in Kent, where it appears as early as the third week 
in March, it is more numerous than the wood wren. In a 
short tour through North Wales I could not discover it, but 
frequently met with the other two species. 
Bewick, in the last edition (1826) of his ingenious work on 
British birds, gives a figure and description of a fourth 
species, under the title of the least willow wren, and says 
that its length is scarcely 44in. I have in vain endeavoured 
to identify this bird, and, till something further is produced, 
shall doubt its being distinct from the lesser pettychaps. 
I trust that some of the readers of this Magazine will attend 
to, and communicate, any facts they may discover likely to 
clear up this point. At the British Museum the yellow wren 
and lesser pettychaps do not appear to be correctly labelled ; 
and I imagine that the bird there marked as the Sylvia 
Natterérz of Temminck is only a lesser pettychaps, the shades 
of plumage varying according to age and sex. 
as i 
Art. VII. Additions to the British Fauna; Class, Fishes. 
By WILLIAM YARRELL, Esq. F.L.S. Z.S. &c. 
Sir, 
Ir the following short notice prove an acceptable trifle for 
insertion in your Magazine, it is quite at your service. The 
subject suggested itself to me on reading the interesting 
observations of your correspondent O., in his account of the 
stickleback. (p. 329.) 
It appears to be but little known that three distinct species 
of three-spined sticklebacks have been constantly confounded 
under the name Gasterésteus aculeatus of Linnaeus; that all 
three of these species are common in our rivers, particularly 
the Thames, although only one of them has been included in 
any British Fauna. 
We are indebted to Messrs. Cuvier and Valenciennes for 
a general description applicable to all three of these fishes in 
the fourth volume of the Histoire Naturelle des Poissons, with 
accurate figures of two of them. The specific distinctions 
of each are also pointed out; and as the old term aculeatus 
applies equally to all of them, this appellation has been drop- 
ped, and new specific names attached to each, which will be 
mentioned in the sequel. 
It is not my intention to occupy any portion of your valu- 
able space with a repetition of that which will be found in the 
Vou. III. — No. 16. MM 
