422 THE AMERICAN NATURALIST. [Vor. XXXIV. 
slender representation of them within our limits. These, how- 
ever, belong to the three principal groups — Tartaridz, Phryn- 
ide, and Thelyphonidz. They are all of moderate to large 
size; there is a patella in at least some of the legs; there are 
no tactile organs on the hind coxa; the mandibles are of mod- 
erate size; the body never ends in a sting; and the palpi are 
never chelate at the end; the abdomen is usually elongate, and 
when short it is not joined broadly to the cephalothorax, as in 
the Phalangida. 
In the Tartaridz the thoracic segments bearing the third and 
fourth pairs of legs are not united to the head, as in most 
arachnids, but free, and their scute showing as separate pieces 
on the dorsum. The abdomen is rather slender, tapering each 
way, and at tip is a long triangular 
telson. The palpi are short and 
terminate in a stout claw. The 
legs, except the first pair, are pro- 
vided with a patella. The Thely- 
phonidz are readily known by the 
presence of a long multiarticulate 
telson or tail; whence the popular 
name of “whip scorpions.” The 
body is depressed and the abdomen 
joined broadly to the cephalotho- 
rax. Our single species, although 
greatly feared, is not poisonous. 
The Phrynidz are separable from the other Pedipalpi by the 
tenuity of the connection between the cephalothorax and abdo- 
men. The body is broad and flat, without a tail. Of the three 
species recorded from our country, two are quite doubtful. 
The Pedipalpi are tabulated as follows : 
Fic. 1. — Admetus. 4, telson. 
— 
B 
Cephalothorax transversely divided in posterior part, no eyes, telson 
short . . (fam. fora ens pentapeltis Cook € 
Cephalothorax entire, eyes pres 
. Abdomen with a long carta TOA abdome quite iain 
united to cephalothorax . . . (fam. Thelyphonide) 
Miside oe Lucas ¢Tex., Fla., Ariz.) 
Abdomen lacking xd telson, ene to pte by slender 
pedis .. . A : (fam. PArynide)3 
N 
