PecUham—Revision of the Attidm of North America. 367 
is black with a whit© spot just before the anterior constriction, 
and a white band in the constriction on each side, which is nar¬ 
rower above than below. Abdomen in front of constriction 
pale rufus; behind constriction black, with a white band which 
occupies the anterior sides and curves downward under the ven¬ 
ter. Legs are all slender; first pair pale, with an external and 
internal black line on the femur patella and tibia; second pair 
all pale; third pair pale, except femur which is dark, and a 
black spot on tibia; fourth pair with femur dark, patella pale 
at proximal, blackish at distab end; tibia, proximal end, black¬ 
ish, shading into pale towards outer part; metatarsus and tarsus 
pale. 
This species is found on plants and low bushes and matures 
in June. The cocoon contains four large eggs, and, to judge 
from the habits of Peckhamia picata, three or four are made 
during the summer. We have elsewhere called attention to the 
low fertility of the ant-like spiders (some species of the Attidse 
lay 180 eggs), and have suggested that if there is an inverse 
variation in every species between its birth-rate and its powers 
of maintenance, we must accept the conclusion that these small, 
weak and defenseless spiders derive an immense advantage 
from their imitation of ants, their mimetic form enabling them 
to escape from their enemies.* 
PECKHAMIA E. S. 1901. 
Type, Synemosyna scorpiona Hentz. 
1845. Synemosyna hentz (picata), Jour. Bost. Soc. Nat. Hist., V. 
1875. Synemosyna hentz (picata), Occ. Pap. Bost. Soc. Nat. Hist., II, 
p. 75. 
1888. Synageles P., Wis. Acad. Sciences, Arts and Letters, VII, N. A. 
Att., pp. 94, 95. 
1891. Synageles E., Trans. Conn. Acad., VIII, p. 32. 
1892. Synageles P., Occ. Pap. Nat. Hist. Soc. Wis., II, 1, pp. 63-65. 
1901. Peckhamia simon, Hist. Nat. des. Araign. 2me Ed., II, p. 496. 
1903. Peckhamia simon, ibid, p. 868. 
1905. Peckhamia banks, Am. Nat., XXXIX, p. 320. 
*Occ. Pap. Nat. Hist. Soc. Wis. Vol. II, No. 2, p. 75. 
