CHAPTEE XIX, 



Genus IBIDORHYNCHUS. 



Charadriid.*: rostro valde arcuato, tarso omnino reticulate 



Diagnosis 

 of genus. 



The Ibis-billed Oystercatcher is the sole representative of the genus which has almost < Generic 

 unnecessarily been established for its reception. 



The diagnosis of the genus Ibidorhynchus may be slightly altered from that of 

 BJcematopus as follows : — 



CharadriiDjE with a much decurved bill, and with the tarsus reticulated all round. 



It probably represents the descendants of a party of Oystercatchers which escaped 

 from the Polar Basin along none of the four coasts which lead from it, but ascended the 

 Yenesay to find refuge in Mongolia from the cold of a Glacial Period. 



It frequents the banks of mountain-streams, and is not known to have visited the 

 coast. It is said to be capable of enduring great cold. 



2s 



