ICHNEUMON-FLIES — GELINAE : MESOSTENINI 19 



largely Eurasian and African genus Schreineria. It has not yet been 

 taken in Mexico but doubtless will be when collecting there is more 

 intense. The Longicaudis group of Mesostenus is an American species 

 group of uncertain affinities. The other four genera are related to 

 Trachysphyrus. The distribution of these groups includes mostly 

 Mexico and southwestern United States, wdth some species in Central 

 America and a few in South America, All are strictly American. 

 In our area, a few species of the group range as far northward as 

 southern British Columbia, and one or a few species of each genus 

 except Reptatrix occm* in southeastern United States. Reptatrix 

 now contains a single species from northwestern United States, but 

 some undescribed Mexican species are related to it and possibly 

 should be included in the genus, 



Neotropic: This group of genera includes Whymperia, Baryceros, 

 Mallochia, ChromocryjJtus, Diapetimorpha, Lymeon, Pachysomoides, 

 Acerastes, Polycyrtidea, Cryptanura, Chamula, Camera, Polycyrtus, 

 Messatoporus, and Agonocryptus. These genera are strictly American, 

 with their general centers of distribution in the Neotropics. They 

 invade the southern portion of the Nearctic region, but there occur 

 mostly in southeastern United States, in contrast to the Sonoran gi-oup 

 of genera which are better represented in the Southwest. Four of the 

 genera {Whymperia, Polycyrtidea, Chamula, and Camera) are repre- 

 sented in our area only by single species along the southern border, 

 Chromocryptus has a single widespread species. The rest of the genera 

 are better represented in the Austroriparian and Carolinian faunas, 

 Baryceros, Mallochia, and Lymeon each has a single species along the 

 southwestern border of the United States and several species in the 

 Southeast. Diapetimorpha, Acerastes, Cryptanura, Polycyrtus, and 

 Agonocryptus occur only in the Southeast. Pachysomoides and 

 Messatoporus range over most of the United States and southern 

 Canada but have more species in the Southeast than elsewhere. 



In the Nearctic region we have just a fringe of these primarily Neo- 

 tropic genera. With us, the genera and species are easy to differen- 

 tiate, but in the Neotropics the very large complexes that occur make 

 some taxonomic problems of monumental proportions. Inexperi- 

 enced workers with Neotropic material at hand should not be deceived 

 by the bright colors and strong sculptm-al characters that seem to 

 make the distinction and description of the species so easy. More 

 complete collections would force an appreciation of the tremendous 

 number of closely related and variable species, subspecies, and genera, 

 which to be treated in a useful way will requu-e larger collections than 

 have yet been assembled, and more time than a casual worker can 

 give. 



