PHAIiANGE^ OF THE UNITED STATES. 11 



it, eye eminence, in our species is mostly dark-colored, 

 and more or less spinate or tuberculate. The eyes are 

 two in number, rather large, simple. Near the anterior 

 margin of the cephalothorax, on each side is an oblique 

 stigmata. These have been mistaken for ej^es, but are 

 openings through the dermal skeleton. 



The spiracles from which proceed the principal trachean 

 trunks in the " Harvest-men " are placed between the pos- 

 terior pair of coxee and the abdomen. 



All of the Arachnida have four pairs of feet, which in 

 the Phalangidte are chiefly remarkable for their length, 

 and the number of their tarsal joints. The coxte are 

 large, conical, and converging towards the sternum. They 

 are almost completely hid by the body of the animal. 

 The next article, the trochanter, forms with the coxa a 

 sort of ginglymoicl joint. The trochanters are small, 

 but often aflbrd good specific characters. The femora are 

 long and slender, and are distally connected with the 

 shorter tibiae, which in turn give attachment to the numer- 

 ous series of short tarsal articles. In the Gonyleptidfe, 

 the last pair of feet are the longest. In the Phalangidas 

 proper, the first and third pairs are about the same length 

 and much shorter than the others ; the fourth pair is not 

 quite so long as the second. 



The question here naturally presents itself, are the 

 most anterior pair of feet true feet, i. e. sternal append- 

 ages, or in other words are the so called octo^Cf?oi(S insects 

 really eight-footed. The use of these organs as feet is of 

 course no argument at all as to their homologies. Besides, 

 in many Arachnids, such as the Phrynidaj and Thelypho- 

 nidtB, they are used almost exclusively as feelers, almost 

 replacing the antennc^ in function, and probably in very 

 many other genera and families they answer the double 

 purpose of limb and palpus. If a true spider be exam- 

 ined, the anterior pair of feet will be seen to be articu- 

 lated to the sternum, and in all respects similar to the 

 others. Nevertheless, I cannot think they are true 

 sternal appendages, for the following reasons. If they 

 be so, the thorax must consist of four segments instead 

 of three, as in the true insects. In the Spiders, in Scor- 

 pions, Harvest-men, etc., the segments of the cephalo- 



