196 FOEMICAEIIDiE. 



b"'. Bostrum compressum. 



THAMNOPHILUS. 



Thammphilus, Vieill. Anal. p. 40 (1816) ; Scl. Cat. Birds Erit. Mus. xv. p. 180. 



Thamnophilus is by far the largest genus of the Formicariidse, containing between 

 sixty and seventy species, according to Mr. Sclater, of which fifty-five were more or less 

 known to him. These are distributed over the whole area of the family, which is 

 represented both in the extreme northern and southern limits by members of the 

 genus. In Mexico and Central America nine species occur, of which two only reach 

 Southern Mexico and Guatemala, the rest all belong to the southern section of our 

 fauna. 



Mr. Sclater divides Thamnophilus into six sections, basing their characters upon size 

 and the colour of their plumage. 



The first Section A, represented by the great T. leachi, is not found within our area, 

 but the other five sections are all present. 



Whether all these sections should be merged under Thamnophilus is a doubtful 

 question, a revision of them would probably result in the recognition of several genera. 

 For them many names are available, proposed at various times, chiefly by Reichenbach 

 and by Cabanis and Heine. T. doliatus is usually considered the type of Thamno- 

 philus. Its plumage is soft and lax, the bill smooth, the culmen slightly curved till 

 it descends rather abruptly to a well-marked but not very prominent hook, before 

 which, at the end of the tomia, is a moderately deep notch ; the tomia of the mandible 

 has also a small subterminal notch ; the tomia of both maxilla and mandible is nearly 

 straight, but the gonys of the latter ascends in a gradual curve ; the tarsi have well- 

 defined scutella, both in front and behind ; the claws are short and curved, and have 

 deep grooves on both inner and outer lateral surfaces. The tail is moderate and rounded, 

 and the wings short and rounded, the fourth to the eighth primaries subequal, third = 

 tenth, the first much the shortest, the second halfway between the first and third. 



T. melanocrissus, belonging to Mr. Sclater's Section B, has much less soft plumage, 

 the bill is more compressed, larger in proportion, and with the terminal hook and sub- 

 terminal notches well developed ; the wings are similarly shaped to those of T. doliatus, 

 but the tail is longer in proportion. The colour of the plumage is pure white beneath, 

 black above in the male, brown in the female. T. bridgesi of Section D, besides its 

 differently coloured plumage, has a differently shaped wing, the second primary being 

 much longer than in T. doliatus, falling little short of the third and fifth, and the 

 fourth the longest in the wing ; the tail, too, is longer in proportion to the wing than 

 that of T. doliatus. T. atrinucha (Section D) has soft plumage like T. doliatus, but 

 differs chiefly in its style of colour being grey and black, but without transverse bars ; 

 the male, too, has the white concealed dorsal spot so frequently present in other Formi- 

 cariidse. T. punctatus, a representative of Section C, has plumage like that of 



