with Descriptions of New Forms. 119 



farther, many of the adults of this tribe having an almost cir- 

 cular pronotum. In describing Etoblattina Peachii Wood- 

 ward (loc. cit.) refers to a prominent notch in the pronotum. 

 From the illustration given it would seem that the notch was 

 not natural, but caused by the decay and more rapid erosion of 

 the pronotum directly over the head, a feature not uncommon 

 in similar iron-stone nodules from Mazon Creek (Text-figure 7). 



Front Wings. — The front wings have been thoroughly 

 studied by Scudder and others, and their distinctive and primi- 

 tive characters pointed out. The four principal veins of the 

 front wings, — subcosta, radius, media, and cubitus, are distinct 

 to the base. In most living forms two or more of the main 

 trunks disappear by fusion with the adjoining veins, although 

 all four can be seen in their original position in the living 

 nymphs (Text-figure 37). The anal area was well marked off as 

 early at least as the middle of the Carboniferous, but the anal 

 veins, as Goldenberg and Scudder have noted, end with rare 

 exception on the inner border, while, as a rule, among living 

 forms the anal veins end on the furrow. The tegmina were 

 for the most part less coriaceous than those of living forms. 

 Well-developed cross veins are comparatively rare. 



Hind Wings. — The hind wings are thinner and more deli- 

 cate than the front and are much less often preserved. They 

 do not fold longitudinally as do the hind wings of living cock- 

 roaches. Cross veins as far as known are absent. The anal 

 area did not present so great a spread as that of modern cock- 

 roaches, and, as Scudder has said, does not seem to have been 

 plaited as in almost all modern forms. The costa is submar- 

 ginal and occasionally gives off one or two superior branches. 

 The veins of this wing are more uniformly developed than in 

 the hind wings of most modern cockroaches. Strength is 

 obtained as in living forms by a subcostal fold. The costal 

 border is nearly straight or a little concave near the base. 

 The inner border is full and well rounded, making the wing 

 broad in proportion to its length (Text-figures 33-36, and 

 Figures 8-10 of Plate I). 



Legs. — The legs are not uncommonly preserved, showing 

 either as impressions through the integument or projecting 

 from beneath the body. The second pair is somewhat larger 

 than the first, and the third longer than the second, indicating 

 that progression was by running. The tibia, of some forms at 

 least, was spinous (Text-figures 8 and 14). The femur, on the 

 contrary, was probably smooth, since well-preserved femora 

 show no indications of spines. The first joint of the tarsus 

 seems to have been comparatively long. The number of seg- 

 ments is not distinct on any specimen at hand, but the tarsus 

 was terminated by a claw (Text-figure 23). 



