ROCKY MOUNTAIN ANTCATCHER. 97 
are the sole, but sufficient marks of difference between 
the two species. 
Pallas’s dipper is longer than the common species, 
measuring eight and a half inches. The bill is perfectly 
similar, and three quarters of an inch long, blackish, 
paler beneath and on the edges. The whole bird, 
without any exception, is of a dark grayish slate colour, 
with the base of the plumage somewhat lighter; at the 
superior orbit is a slight indication of whitish. The 
uniform general colour is somewhat darker on the head, 
and a shade lighter beneath. The wings are three and 
a half inches long, as in the genus; the coverts and 
tertials slightly tipped with dingy whitish; the primaries 
incline somewhat to brown. The tail measures one 
inch and a half, and is perfectly even. The feet are of 
a flesh colour, and the nails dusky white : the tarsus is 
precisely one inch long. 
If we could rely on Brehm, four species of this genus 
exist, which are all found in the old continent. Two 
are new ones, proposed by himself, under the names of 
Cinclus septentrionaiis and Cinclus melanogaster. The 
latter, according to him, is a Siberian species, appearing 
occasionally on the northern coast of European Russia 
in winter, and is, perhaps, a genuine species, easily 
distinguished from the Cinclus aquaticus , by having 
but ten feathers in the tail, whilst all others have 
twelve, in addition to its smaller size, darker colour, 
and dingy throat; but the former can hardly be re- 
garded even as a northern variety produced by climate. 
Mr Brehm is probably quite correct in observing, that 
both liis new species are perfectly similar to the old one. 
GENUS XI. — MY 10 THERA, Bonaparte. 
20. MYIOTHERA OBSOLETA , BONAPARTE. 
ROCKY MOUNTAIN ANTCATCHER. 
BONAPARTE, PLATE I. FIG. II. 
This bird is one of those beings which seem created 
to puzzle the naturalist, and convince him that nature 
VOL. iv. g 4 
