i68 obrrhoi.srr: diagnosis of a nivW grnus of bucrrotidae 



Remarks. — This new genus diflfers so much from the other PhiHppine 

 genera, and in fact from all of the genera of the Bucerotidae, that a 

 close comparison is scarcely necessary. It is, of course, apparently 

 most nearly allied to Hydrocorax, although it is so different in ap- 

 pearance from Hydrocorax hydrocorax, the type of that genus, that it is 

 rather remarkable that it has not been separated before. It should be 

 stated, however, that Dr. Edgar A. Mearns had noticed the very 

 striking structural characters in Hydrocorax semigaleatus Tweeddale, 

 and just before his untimely death had planned to create a new 

 generic group for this species. 



The third species commonly referred to the genus Hydrocorax, 

 Hydrocorax mindanensis (Tweeddale), has a smaller casque than 

 Hydrocorax hydrocorax, but it is of the same shape, and the species is 

 without doubt correctly placed in the same genus. The type of our 

 new genus, Platycorax semigaleatus (Tweeddale), is, therefore, its only 

 species. 



The only other generic name applied to any species of Hydrocorax 

 is Platyceros Cabanis and Heine, ^ the type of which is Hydrocorax 

 hydrocorax; so that it is, of course, a synonym of Hydrocorax Brisson. 



By the present separation of Platycorax, there are now five genera 

 of Bucerotidae in the Philippine Islands, of which four, including 

 Platycorax, are endemic, 



* Mus. Hein. 2: 174, i860. 



