with Descriptions of New Forms. 227 



Homologous veins bear the same number. The close simi- 

 larity is very apparent, The modern cockroaches thus present in 

 their ontogeny an interesting illustration of the recapitulation 

 of ancestral characters. 



EXPLANATION OF PLATE I. , 



Figure 1. — Mylacris elongata Scudder. An adult, slightly enlarged. 

 Same specimen as illustrated by Text-figure 8. The head projects in front 

 of the pronotum. The abdomen is noticeably short in comparison with the 

 thorax and long wings. 



Figure 2. — Etoblattina mazona Scudder. Nymph with ovipositor pre- 

 served. Same specimen as Text-figure 1 3. 



Figure 3. — Mylacris (Dipeltis) diplodiscus Packard, sp. Type specimen. 

 The head projects from beneath the pronotum. The impressions of the first 

 pair of legs are indistinctly seen through the integument. The femora of 

 the second pair of legs can be detected in the photograph. For a line draw- 

 ing of the specimen, see Text figure 4. 



Figure 4. — Etoblattina Hilliana? Scudder. 



Figure 5. — Spiloblattina maledicta Scudder. sp. The wing shown in this 

 photograph, also in Text-figure 26, is of the form or variety of the species 

 with arched costal border and short cubital area. 



Figure 6. — Spiloblattina maledicta Scudder, sp. Typical wing of the 

 sjjecies having slightly arched costal border correlated with great extent of 

 the cubitus. Same as Text-figure 27. 



Figure 7. — Gerablattina arcuata sp. nov. Type specimen. The wing, 

 as the photograph shows, has light and dark areas similar to those of Spilo- 

 blattina, to which genus possibly the species should be referred. The same 

 specimen is illustrated by Text-figure 1. 



Figures 8, 9. — Etoblattina sp. Detached hind wings. Same specimens 

 as Text-figures 34 and 35. 



Figure 10. — Spiloblattina maledicta Scudder, sp. The hind wing is of 

 thinner texture and has color area similar to those of the front wing. 



Figure 11. — Etoblattina coriacea sp. nov. Same as Text-figure 29. 



Figure 1 is but slightly enlarged ; Figure 3 is a little less than twice nat- 

 ural size ; all others are enlarged approximately two and one-half diameters. 



Figures 1-4, from the Coal Measures of Mazon Creek, Illinois ; all others 

 from the Upper Coal Measures of Lawrence, Kansas. 



Originals of Figures 1, 2, and 4, in the Yale University Museum ; of Figure 

 3, in the National Museum ; all others, in the University of Kansas Museum. 



