Dec, 1845.J 301 



crease, and the white parts increase in size and intensity in ascending. In 

 septentrionalis the outer weh of the lateral tail feather is entirely white, ex- 

 cept a small portion near the base, where there is a slight tinge of grey next 

 the shaft, and the quills, secondaries and all the tail feathers are margined 

 more broadly and with a purer white than in the other species. 



I have given a table showing the comparative measurements of the three 

 American species of this division of the genus Parus having black heads, 

 which so closely resemble each other in voice, habits and markings; and 

 have also added some measurements from a paper in the Archives of the 

 Academy, by M. de Selys-Longchamps, Corresponding Member of the 

 Royal Academy of Brussels, extracted from their Bulletin, vol. 10, No. 7. 

 I have reduced his measurements to English inches and decimals, and have 

 given my own also in decimals for more ready comparison. It will be seen 

 that his specimen from Iceland (frigoris) corresponds so nearly with our 

 atricapillus as to render it probable that it is identical, while his utricapillus 

 from Brisson is so near to Audubon's Carolinensis as to render it almost certain 

 that the description of P. atricapillus by the old authors was from our small 

 southern bird. If this opinion be correct, our Carolinensis should resume the 

 name of atricapillus, and the larger bird be called frigoris, as suggested by 

 M. de Selys-Longchamps. 



The note of this bird is similar to atricapillus, but its voice more liquid, 

 and less harsh and querulous in the utterance. Bill longer and stouter. 



Length. Wing. Tail. Length. Wing. Tail. 



Parus Carolinensis 4\ 2| 2f or 4.250 2.500 2.375 



» atricapillus 5| 2 J* 2,9 5.125 2.687 2.562 



« septentrionalis (Nob.) 5| 2'3 3H 5.875 2.812 3.093 



" atricapillus (Briss.) ) from the paper of M. de 4.794 2.397 



" frigoris \ Selys-Longchamps. 5.149 2.663 



It will be seen by the above table, that while in each of the old American 

 species the wingis .125, or § of an inch longer than the tail, in the new bird, 

 the tail is .281, or nearly^ of an inch longer than the wing,- compared with 

 atricapillus, the total length is greater by f of an inch, the wing by f , and 

 tail by 8| r more than half an inch. 



16 



The colours in this immature specimen are only t»be depended upon as 

 showing the much greater development of the white, and smaller extent of 

 the black markings, than in the other species. For the sake of more easy 

 reference, the description has been made parallel with those ofAudubon in 

 his Synopsis. I would propose as an appropriate English name for this bird, 

 the <; long-tailed black-cap Titmouse." 



