122 



NATURAL HISTORY OF ARTHROPODS. 



FIG. 176. Gonyleptcs curvipes. 



states Phalangium dorsatum, a grayish species with a darker dorsal band, is very 

 common. Cosmetus ornatus occurs in the southern states, while Acanthocheir 



armatum is a blind form found in Mammoth Cave. 

 These forms have an inflated, oval body, and the 

 hinder femora unarmed. The family TROGULID^E, 

 with a flat, elongate abdomen and the cephalothorax 

 produced forwards, covering the mouth-parts like a 

 roof, has not been reported from America. 



SUB-ORDER II. - - PEDIPALPI. 



These forms, which are commonly known as 

 whip-scorpions, are all inhabitants of tropical and 

 semitropical countries. They have eight ocelli, two 

 in the median line and three on either side. The 

 chelicerse are short and two-jointed, while the palpi 

 are long and large, terminating in a more or less 

 perfectly formed pincer. The first pair of legs is the longest, and the tarsal joint is 

 broken up into a long series of articles, well shown in our figure of Phrynus. The 

 abdomen is slightly constricted at the base, and is composed of eleven or twelve joints. 

 There are two pairs of stigmata. 



Two well-marked types exist, forming the genera Phrynus and Thelyphonus, each 

 of which may be regarded as forming a family to which the names PHRYJSTID.E and 

 THELYPHONID^E are re- 

 spectively applicable. 



In Phrynus the palpi 

 are very long, the carpal 

 joint strongly spined. 

 The first pair of legs 

 are long, and both the 

 tibial and tarsal joints 

 are broken up into a 

 series of rings. The 

 abdomen is oval. The 

 young are born alive. 

 The species are all trop- 

 ical, none occui'ring 

 within the limits of the 

 United States, though 

 Phrynus asperatipes 

 occurs in Lower California ; a second species is found in the West Indies, and two 

 more are known from Southern Mexico and Central America. Other forms are found 

 in the tropics of both hemispheres. 



ThelypJiomis is much more scorpion-like in appearance, and to the species of this 

 genus the name whip-scorpion is most applicable. The palpi are short and stout, and 

 the joints are covered with stout, sharp spines ; the first pair of legs is very long, but 

 only the tarsus is broken up into small joints. The abdomen is long and somewhat 

 slender and twelve-jointed, the last three joints being much smaller than the rest. 



FIG. 177. Acanthocheir armata, enlarged. 



