Nov., '08] ENTOMOLOGICAL NEWS. 433 



4 wings 9 obsoleta, and 4 wings $ .vanthosoma; crossed in I 

 wing 9 obsoleta. Two cubito-anal cross-veins in front wing 

 in 21 wings $ and 16 wings 9 yamaskanensis, 2 wings $ 

 and 5 wings 9 obsoleta; 3 cross-veins in i wing 5 yamaska- 

 nensis and 3 wings 5 .vanthosoma; 4 cross-veins in i wing $ 

 xanthosoma. One cubito-anal cross-vein in hind wing in i 

 wing $ yamaskanensis; 2 cross-veins in 21 wings $ and 16 

 wings 9 yamaskanensis, and 2 wings 5 and 5 wings 9 ofoo- 

 /^fa; 3 cross-veins in 4 wings $ .vanthosoma. In 2 males yama- 

 skanensis and i 5 obsoleta the anal triangle is 2-celled, in 2 

 <J xanthosoma 3-cellecl. Antenodals in front wing yamaska- 

 nensis 9-11, obsoleta 7-8, .vanthosoma 7-8; postnodals in front 

 wing yamaskanensis 6-9, obsoleta 7-10, .vanthosoma 7-8; ante- 

 nodals in hind wing yamaskanensis 6, obsoleta 5 (rarely 6), 

 xanthosoma 5 : postnodals in hind wing yamaskanensis 7-10, 

 obsoleta 8-10, .vanthosoma 7-8. Rows of cells after triangle in 

 front wing yamaskanensis 2, obsoleta and .vanthosoma 2 or 3 : 

 in hind wing yamaskanensis 2 or 3, obsoleta 2, and .vanthoso- 

 ma 2-4 indefinite. Material studied by me yamaskanensis 2 5 , 



1 9 ; obsoleta i 5 , 2 9 and wings figured by Martin p. 38, 

 Cordulincs, Coll. Zool. Selys Longchamps; and .vanthosoma 



2 $. 



The abdominal appendages of Platycordulia .vanthosoma are 

 figured. They are separated at once from species of Neurocor- 

 dulia by the inferior tooth of the superior appendages. 



The two males of P. .vanthosoma in my collection were taken 

 at Wister, Oklahoma, one of them on June 4, 1907, by myself, 

 the second on August 2, 1907, by Frank Collins, a boy who 

 did some collecting for me. Wister is situated in the northeast 

 part of the Choctaw Nation, a few miles south of parallel 35 

 deg. N., near the Poteau River, a southern affluent of the Ar- 

 kansas. About a mile north of the town is a lake lying on 

 the west side of the railroad. I was informed that this lake is 

 artificial, caused by the fill for the railroad grade. At the 

 present time the lake has a surprising Odonate fauna. 

 To mention two cases, Libellula cyanca and Ischnnra 

 kcllicotti, hitherto not known west of Indiana, were here in 



