200 S&. H. Scudder—Rocky Mountain Triassic Insects. 
other cockroach, ancient or modern, so far as I know; but 
otherwise it is related to Etoblattina; while Poroblattina 18 
more nearly related to Petrablattina, and especially to the two 
new species of that genus from this locality. 
he average size of these Fairplay Paleoblattariz is much 
less than that of the Paleozoic Palzoblattariz in general. 
The average length of the front wings of the Paleozoic species 
is 26"; that of these Fairplay Paleoblattaria, 16™. This 
fact has its value, for the Jurassic species are nearly all of very 
small size, and the wing-length of the remaining species trom 
* Zeitschr. deutsch. geol. Gesellsch., 1880, p. 510. 
