APPENDIX, '331 



MYRMOSA, Latr. 



M. unicolor. Black; abdomen with cinereous hair; me- 

 tathorax with an impressed line. 



Inhabits North-west Territory. 



Head with short cinereous hair, somewhat longer about 

 the mouth; densely punctured ; thorax and scutel densely 

 punctured, and with scattered cinereous short hair ; poste- 

 rior segment of the former with two light parallel impress- 

 ed lines; wings hyaline, nervures fuscoUs ; metathorax 

 with a longitudinal, impressed, very distinct line ; and a 

 transverse one at base ; hair more obvious each side ; punc- 

 tures smaller than those of the thorax j abdomen more 

 hairy than any other part of the body. 



Length three-tenths of an inch. 



This insect also occurred on the Missouri, at Engineer 

 Cantonment, and in Pennsylvania. 



TIPHIA, Fahr. 



1. T. inornata. Black, immaculate; wings yellowish- 

 fuliginous. 



Inhabits Ohio and Pennsylvania. 



Head punctured ; antennse piceous, paler towards the 

 tip ; mandibles piceous, blackish at tip ; thorax punctured, 

 wing-scale and posterior margin of the first segment im- 

 punctured, edge of the latter piceous ; metathorax with 

 three longitudinal, slightly elevated lines ; posterior edge 

 also slightly elevated into an acute line ; feet hairy, tibia; 

 and tarsi more or less piceous ; abdomen^ particularly be- 

 hind, hairy. 



Length three-fifths of an inch. 



