104 Bulletin Wisconsin Natural History Society. [Vol. 8, No. 2. 



among- the (Jorduliina: of the Aeschnosoma group than among the Libel- 

 lulinw. The internal triangle will do for such a Corduline (and would 

 do for many of the LibellulinwJ . 



7. The rather particular form of the discoidal field, produced by 

 the waved form of M 4 (and less so M 3 ) is not known to me among the 

 LibelluUnce, In Scudder's figure it is somewhat intermediate between 

 the forms of Aeschnosoma and Neocordulia volxemi. 



8. The form of the radial supplement is very much like that of 

 the mentioned Corduline genera. 



9. The postnodal part of the wing is relatively too long for Aesch- 

 r.osoma (which has nearly the proportions of Macromia or Macro- 

 llic-ms), but is much like <V eurocordulia and Plat ijcordulia. 



10. Little importance can be attached to the anastomosing of the 

 .sectors of the arculus in Scudder's figure. The long stalk is even far 

 too long for any of the Libellulinm. I think either the conservation of 

 the specimen or a mistake of the artist are responsible for this impos- 

 sible feature of the wing.- 



My conclusion: Needham is right (as might be expected 

 from one who has so profoundly studied the development of 

 dragonfly venation). The specimen as figured by Scudder is not 

 a Gomphine ; it is a Corduline, more especially something between 

 N eurocordulia and Platycordulia on one side, Aeschnosoma on 

 the other side. 



2. Trichocnemis aliena Scudder. 



The figure of this fossil appears on the same plate with Steno- 

 gomphus. 



There is little reason to look for such a far off relationship as 

 that of Trichocnemis for Scudder's fossil; (it must be remem- 

 bered that the "legion Platycnemis" is not represented in America 

 at all). The wing seems to me most probably a hind wing of 

 Argia. If compared to nature, one will find that the quadrangle 

 in Argia (hind wing) is much like that figured by Scudder; the 

 proportions of sectors, the origin of Cu 2 , the position of the nodus, 

 the number of postnodals, too, correspond with Argia. The sec- 

 ond cubito-anal cross-vein is very probably either anomalous for 

 an addition by the artist (more probably the second) ; it would 



2) In a letter dated June 1, Dr. Ris writes: " — since writing, I received 

 from the Hamburg Museum an Aeschnosoma forcipula, labelled by de Selys ; 

 this specimen shows remarkable similarity to S.carletoni — supposing that the 

 stalked sectors of the arculus n the latter are, as quite possible, due to casual 

 superposition of the veins in the fossil." — R. A. M. 



