56 



bulletin: museum of comparative zoology 



Tryphoninae. 



This subfamily is not very abundantly represented in the Florissant 

 fauna, although I have recognized species belonging to six genera, 

 all of them, modern and occurring in this same region at the present 

 day. These are Mesoleptus, Tryphon, Orthocentrus, Camerotops, 

 Exochus, and Tylecomnus. 



According to Brischke ('86) Mesoleptus and Tryphon occur in 

 Baltic Amber and Scudder ('90) has described an Eclytus from the 

 Oligocene of Green River, Wyoming. Bassus has been said by Kefer- 

 stein ('34) to occur in Baltic Amber. 



Mesoleptus Gravenhorst. 



Key to the Florissant species of Mesoleptus. 



Areolet open M . apertus, sp. nov. 



Areolet closed M. exstirpatus, sp. nov. 



Mesoleptus apertus, sp. nov. (Fig. 41.) 



Female. Length 5 mm. Body black or dark colored, the apical segments 

 of the abdomen brownish; wings slightly infuscated. Head, thorax, and first 



abdominal segment smooth 

 and highly polished. An- 

 tennae moderately slender, 

 their apices not preserved in 

 the type specimen; basal 

 flagellar joints from two and 

 one-half to four times as long 

 as thick, those toward the 

 apex somewhat transverse. 

 Mesonotum without furrows. 

 Scutellum strongly convex, 

 with a large, broad groove at 

 its base; metanotum com- 

 pletely, very regularly and 

 distinctly areolated, its sur- 

 face polished. Abdominal 

 petiole slightly shorter than 

 the metathorax, with two 

 widely separated longitudinal discal carinae. Abdomen suddenly widened 

 behind the petiole, oval in shape. Ovipositor one-half as long as the abdo- 



Fig. 41. — Mesoleptus apertus, sp. nov. Type. 



