24 FOSSIL INSECTS OF THE BRITISH COAL MEASURES. 



association which exists at Coseley, Sparth Bottoms, and elsewhere is not due 

 to the accident of deposition or transportation, but the natural result of the 

 conditions under which insect life was passed. 



SYSTEMATIC DESCRIPTIONS. 

 Order PAL^ODICTYOPTERA (Goldenberg), Handlirsch. 



1877. Goldenberg, Die Fossilen Thiere aus der Steinkoblenformation von Saarbruckeu. Fauna 



Sarsepontana Fossilis, pt. ii, p. 8. 

 1906. Handlirsch, Die Fossilen Insekten, p. 61. 



Slender insects with moderate-sized head and biting jaws, simple antenna?, 

 and two pairs of equal and similarly shaped wings. The wing-venation is not 

 unlike the hypothetical tracheation of the primitive nymph worked out by 

 Comstock and Needham ('American Naturalist,' vol. xxxii, no. 374, p. 85, fig. 4, 

 189899). 



The wings could not be folded, being outstretched laterally in the position 

 of rest, and only moving in a vertical plane at right-angles to the body. The 

 thoracic segments are three in number, with wing-like pleurites in some cases 

 on the first segment. The abdomen has eleven segments, the eleventh segment 

 bearing cerci. Legs all similar, and fitted for running. 



Goldenberg did not define the characters of the Order, but included in it a 

 group of Palaeozoic insects which, while somewhat related to the existing forms 

 of Neuroptera, are sufficiently unlike to prevent their inclusion in the latter 

 Order. 



Handlirsch defined the Order as a primitive generalised group, probably the 

 ancestors of all later insects, and wholly confined to the Palaeozoic. He considered 

 that the larvas were predatory and aquatic, developing their wings gradually 

 without resting stages, and being in other respects similar to the imago. His 

 diagram 0f the primitive Pala3odictyopteroid wing shows a slight advance upon 

 the primitive nymph of Comstock and Needham, the primary tracheation being 

 increased by the development of cross-nervures, uniting to form a mesh work. 



Family DICTYONEURID.E, Handlirsch. 



1906. Handlirsch, Die Fossilen Insekten, p. 63. 



1919. Handlirsch, Eevision der Palao/oischen Insekten, p. 3. 



Palaeozoic insects in which the wings possess a close reticulated neuration 

 between the principal veins, the latter strong and parallel over the first third of 

 the wing. Branches of the radial sector, median and cubitus few in number, and 

 strongly curved back to the inner margin. 



Handlirsch regards this family as closely related to Microdictya. 



