1913.] NATURAL SCIENCES OF PHILADELPHIA. 233 



COxMPARISON OF ThAUMATONEURA (iNOPINATA AND PELLUCIDA) 

 WITH PhENACOLESTES. 



{Til. inopinata cf 9, Th. pellucida d^ , Costa Rica). 



These two genera agree in the characters above numbered 2, 11, 

 14 (except as noted below), and 21a. As regards character 11, the 

 separation point of Rs in Thaumatoneura varies and may be a Uttle 

 proximal to, at, or a Httle distal to, the subnodus. 



The two genera differ in characters given below; after each nmnber 

 the difference shown by Thaumatoneura is stated: 



1. Nodus at about one-fifth of the wing-length. 



3. Postnodals very numerous, about 70. 



4. Proximal edge of stigma more obhque. 



5. Cells more elongated at right angles to long axis of wing. 



6. Stronger caudal curvatures of the veins generally as the}' approach 



the hind margin of wing. 



7. The one row of cells between lsl\ and Mia increases to about 



10 rows at the wing-margin. 



8. The one row of cells between ]Mia and M2 increases to 6+ rows 



at the wing-margin. 



9. M2 separates from Mi at nearly one-half way from nodus to 



stigma and at a less acute angle. 

 10. Between M2 and Rs at the wing-margin are 6-7+ rows of cells. 



12. Between Rs and Ms at the wing-margin are 7-8 -f- rows of cells. 



13. Arculus at the second antenodal. ' 



14. Ms separates from M1+2 at a less acute angle. 



15. Between ^h and M4, (a) no cross-veins proximal to the level of 



the subnodus, (6) at the wing-margin 10-|- rows of cells. 



16. Quadrilateral with ia) its proximal and distal sides subparallel 



and (6) subeciual. 



17. Between ]\I4 and Cui are (a) 3-6 antenodal cells and ih) at the 



wing-margin 8+ rows of cells. 



18. Cubito-anal cross-veins two, one proximal to the level of the 



first antenodal cross-vein, the other below the middle of the 

 quadrilateral. 



19. Between Cui and Cu2 at wing-margin are about 12 rows of cells. 



20. Area posterior to Cu2 much larger, Cu2 with many branches. 

 216. Anal vein separates from the hind margin of the wing distad to 



the level of the proximal cubito-anal cross-vein. 

 22. Anal cross-veins proximal to the level of the distal end of the 

 quadrilateral 3-5. 



Relationships of Thaumatoneura. 



Some words maj' be added here as to the retention of Thaumato- 

 neura in this group after the diverging opinions of Professors Needham 

 and Foerster. The late Mr. McLachlan, on describing Thaumato- 



