MORSE: ORTHOPTERA OF NEW ENGLAND. 417 
ing animal whose eggs are laid in underground passages excavated 
by other tools. All of these peculiar features of structure are 
evidently correlated with the subterranean mode of life. 
" With a pair of fore-feet, curiously adapted to the purpose, it 
burrows and works under ground like the mole, raising a ridge as 
it proceeds, but seldom throwing up hillocks" (Gilbert White). 
Key to Species of Mole-crickets. 
A. Large species, one to one and a half inches long (25 to 37 mm.). Hind 
femora scarcely longer than fore femora. Hind tarsi distinct, three- 
jointed. Ocelli two Subfamily Gryllotalpinae. 
B. Hind tibiae armed on distal half of inner (hinder) dorsal edge with four 
spines Euroi)ean Mole-cricket, Gryllotalpa gryllotalpa, p. 419. 
BB. Hind tibiae not so armed. 
American Mole-cricket, G. hexadactyla, p. 417, 
AA. Small species, about one-third of an inch (8 to 9 mm.) long. Hind 
femora greatly enlarged, four to five times as long as fore femora. 
Hind tarsi spur-like, one-jointed. Ocelli three. Subfamily Thidactylinae. 
Pygmy Mole-cricket, Tridaclylus apicialis, p. 420. 
American Mole-cricket. 
Gryllotalpa hexadactyla Perty. 
Fig. 75. 
Gryllotalpa hexadactyla Perty, Del. Anim. Art., p. 119, pi. 2.3, fig. 9 (1830- 
1834). 
Gryllotalpa brevipennis Harris, Treati.se, 3d ed., p. 149 (1862). 
Gryllotalpa borealis Harris, Treatise, 3d ed., p. 149, note (1862). — Fernald, 
Orth. N. E., p. 14 (1888).— Walden, Bull. Geol. Nat. Hist. Surv. Ct., no. 
16, p. 149 (1911). 
Gryllotalpa Columbia Fernald, Orth. N. E., p. 14 (1888). 
Rusty brown to dark brown, paler beneath; the veins of the 
tegmina dark brown on a lighter ground. 
Measurements. 
Body Pronotum Tegmina Wings pass teg. Hind femora 
Male 22 8 7.5 2 7 
Female 25-31 9-10 9-13 2-4 or 13-14 7.5-8 mm. 
This is a distinctly smaller and less robustly built insect than 
the European species, but is otherwise generally similar in struc- 
ture and appearance, though readily recognized by the diagnostic 
characters pointed out elsewhere. The wings vary greatly in 
