114 A. MATTHEWS. 



pion and others. The descriptions of these will be found in their proper 

 places, but to the "Synoptic Tables" of Trichopteryx and Ptenidium I 

 have added them as an appendix, being unwilling to upset the whole of 

 the previous arrangement by the insertion of so many new species. The 

 fact of these recent discoveries will also account for a want of uniformity 

 among the descriptions; the species especially belonging to the United 

 States I have described in detail, in Latin as well as English, but such as 

 have been found only in Central America are merely characterized in a 

 manner sufficient, I believe, to ensure their future identification. 



The Tribes and Genera have been arranged in accordance with the 

 new System of Classification, in which the Trichopterygidae immediately 

 follow the Staphylinidre, and for that reason I have commenced with the 

 Hydroscaphina. I feel convinced that Hydroscapha is merely a Tribe of 

 Trichopterygidae, and not a separate Family. In all its anatomy, and 

 especially in the perfectly normal form of the wing, its affinity to the 

 Trichopterygidfe is far too strongly marked to admit of its separation 

 from that Family. The Trichopterygina naturally follow the Hydros- 

 caphina, and the Ptiliina lead from them into other Clavicorn Families. 



Synoptic Table of Tribes and Genera. 



Habits aquatic HYDROSCAPHINA. 



Habits terrestrial. 



Elytra truncate TRICHOPTERYGINA. 



Elytra entire PTILIINA. 



Elytra truncate TRICHOPTERYGINA. 



Antennae very short, 9-jointed Liiinulodes. 



Antennae elongate, 11-jointed. 

 Pronotum widest at the base. 



Base of pronotum arcuate Myrinicotricliis. 



Base of pronotum not arcuate. 



Ventral segments 7 Pteryx. 



Ventral segments 6. 



Posterior coxse veiy widely separated ; mesosternum scarcely carinate. 



Ptinelludes.^ 

 Posterior coxEe moderately separated; mesosternum evidently carinate. 



Trichopteryx. 

 Pronotum widest before the base. 



Mesosternum carinate Smicrus. 



Mesosternum not carinate. 



Body opaque, abdomen moderate ^.Mephaiies. 



Body translucent, abdomen very long Ptinella. 



.* In Ptinellodes the thorax of % is dilated above the base. 



