48 DIPTERA OF NORTH AMERICA. 



III. CORIACEA. 

 Pam. lxii. hippoboscidae. 



Charact. — Head flattened; first joint of all the tarsi, or at least of the an- 

 terior and middle tarsi, abbreviated. 



N. A. possesses species of the genera Hippobosca Linn., Melo- 

 phagus Lutr., Ornitiiomyia Leach, and Olfersia Wied., several 

 of which are perfectly identical with European species. 



Pam. LXIII. NYCTERIBIDAE. 



Charact. — Head not flattened; first joint of all the tarsi rather long or 

 very long, in comparison with the following. 



One Strebla only and a species belonging to a new genus are 

 known to me as occurring in N. A. 



