438 



NORTH AMERICAN INDEX FOSSILS. 



posterior branchlets, partly furcate; first anal forked, second 

 simple; anal area small, not defined; the wide space between R 

 and Rs filled by polygonal cells; cross-veins in other interspaces 

 simple and distant. 



Order PROTODONATA Brongniart. 



This order includes lo described species of which only 3 are 

 American ; one from the Kanawha of Pennsylvania, Palaeotherates 

 pennsylvanicus Handl., another from the Freeport horizon of 

 Rhode Island, Paralogus aeschnoides Scudder, and the third, the 

 remarkable Tupus permianus Sellards (Fig. 1743), from the Permic 

 of Kansas. The members of this order represent connecting Hnks 

 between the Odonata and the Palaeodictyoptera. The neuration of 



Fig. 1743. Tupus permianus '$)€[\Q.vds, a Permic dragonfly from Kansas. The type 

 specimen about X /^- Specimen viewed from under side, the base of the wings pass- 

 ing under the body. The strongly outUned structures, on the under side of the head 

 are apparently the mandibles ; the distal end of the femur, the tibia and a part of the 

 tarsus of the left front leg are preserved, also a small part of the tibia of the second pair 

 of legs. (After Sellards.) 



the four equal wings is more highly specialized by coalescence of 

 several longitudinal veins in the basal portion of the wing, by con- 

 version of longitudinal veins into " accessory sectors " and by the 

 regular arrangement of cross-veins. Many of the characteristic 

 wing structures of the Odonata, such as the pterostigma, wing 

 triangle, and quadrangle, and the reduction of anal veins, are still 

 wanting in this order. As shown by Sellards, however, the inter- 

 section of longitudinal veins, i. e., the crossing of M^, o by the 

 radial sector, indicated in the adult by the oblique cross-vein at, or 

 just beyond, the separation of M^, o, and a similar, but faint oblique 

 vein (subnodiis) , uniting R and M-^, features so characteristic of 

 modern Odonates is also found in Tupus permianus Sellards, and 

 thus indicates a closer relationship between the Palaeozoic and later 

 Odonates than before recognized. 



