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SIPHONAPTERA. 155 
Vertex evenly rounded from occiput to mouth, slightly flattened above in male; 
head with very weak bristles; bristles on joint 2 of antenn# longer than third joint, 
which is without bristles; mandibles attaining three-fourths of anterior cox; pro- 
notal com) of 18 to 22 spines; legs with strong spines on tibiw and hind tarsi; hind 
femora with a row of bristles on the side; in middle tarsi joint 2 is longer than 5; in 
hind tarsi joint 1 is about as long as 2 and 3 together, while 5 is shorter than 3; 
abdominal segments each with two dorsal and two ventral rows of numerous bris- 
tles, the second dorsal row with 12 to 14 bristles, the ventral row with nearly as 
many, ventral bristles not stronger than dorsal; male claspers long, linear, edges not 
parallel, end somewhat obliquely cut off, rounded; color, brown; length of male, 
2.25 mm., of female 3 to 3.25mm. (Baker.) 
The form described as Pulux ignota by Baker is evidently a female 
of this species, and, since it appears to be a Typhlopsylla, the name 
americana had better be retained. 
Aside from the species mentioned above in the genus Typhlopsylla, 
Kolenati has described octactenus, hexactenus, pentactenus, and dictenus 
occurring on bats in Europe, Tacshenberg wnipectinata on bat in Europe, 
musculi from rats and mice in Europe, caucasica on Spalax typhlus in 
the Caucasian Steppes, gracilis on Talpa europea and Sorex vulgaris in 
Europe, and Baker has described alpina from mountain rat, George- 
town, Colo., and fraterna from garden mole, Lansing, Mich., and Brook- 
ings, S. Dak, host unknown. 
