488 PASSERIFORMES : FORMICARIIDAE CHAP. 
Fam. X. Formicariidae.—The so-called “ Ant-birds ”—not 
known to live on ants—are plentiful in the forests of northern South 
America, whence the numbers decrease to Central America, Chili 
and Argentina. Of the two hundred or more species none inhabit 
the Antilles, but three occur in Trinidad and one in Tobago. Mr. 
Sclater * allows as provisional Sub-families the strong Zhamnophil- 
inae, the weaker Mormicariinae, and the long-legged Grallariinae. 
The beak is strong, compressed, hooked, and terminally toothed 
in the Thamnophilinae, being exaggerated in Satara, large and 
swollenin Cymbilanius,and exceptionally hooked in the former genus 
and Pygoptila ; Cymbilanius, Neoctantes, and Clytoctantes have 
the genys upturned. In the Formicariinae the bill is weaker 
and but shghtly hooked, being very long and thin in RLhampho- 
caenus ; in the Grallariinae it is usually elevated and compressed, 
though broad in Pittasoma. The taxaspidean metatarsus (p. 471) 
is moderate or short in the Thamnophilinae, and remarkably long 
in the Grallarinae, where it may be very strong, as in Pittasoma ; 
among the Formicariinae it is short and thick in Rhopoterpe and 
Formicivora, long and thin in Psilorhamphus and Formicarius, 
and so forth. In Phlogopsis, Psilorhamphus, Rhamphocaenus, 
Heterocnemis, Myrmeciza, Hypocnemis, Pithys, and Gymnopithys 
the scutes are nearly fused. The outer and middle toes are joined 
towards the base. The wings, which have ten primaries and 
nine secondaries, are normally short and rounded, though longer 
in Rhopoterpe; the tail is commonly long and broad in the 
Thamnophilinae, varies greatly in the Formicariinae, and is very 
short and square in the Grallariinae. It may be rounded or 
graduated in the first two Sub-families, and Zerenwra has it 
remarkably thin; Cercomacra, Formicivora caudata, and F. ferru- 
ginea have only ten rectrices in place of the usual twelve. 
Thamnomanes has well-developed rictal bristles, Rhamphocaenus 
has the nostrils in a groove and partly covered by a membrane. 
The sexes are similar, and mainly reddish-brown, in Rhampho- 
caenus, Phlogopsis, and the Grallariinae ; but generally the males 
are black and white, black, grey and brown, or uniform black ; 
and the females ferruginous, more or less reheved by black and 
white. Cross-bars, spots, and striations are not uncommon, 
the white often shewing as a band on the tail, an edging to the 
Wing-coverts, or exceptionally, as in Pygoptila margaritata, as 
1 Cat. Birds Brit. Mus. xv. 1890, p. 177. 
