(J7S CHILOGNATHA. 



Western States. In Polyxenus the body is short, clothed with 

 short penicillate scales, and there are thirteen pairs of feet. 

 (These scales, or hairs, as has been remarked to us by Mr. 

 Sanborn, are remarkably like the hairs of Derinestes, and this 

 homology is another proof that the Myriapods are an order of 

 the class Insecta.) P. fasciculatus Say is about a tenth of an 

 inch in length. It has been detected by Mr. Sanborn under 

 the bark of trees near Boston, and I have found it in Salem in 

 the same situations, and also at Nantucket. 



JULID^E Leach. Thousand Legs. Millepedes. This group 

 cml traces the t}-pical species of this suborder. The body is 

 almost perfectly cylindrical, with the sternum greatly reduced 

 in size, those of the posterior subsegments being almost 

 absent, while the tergum is great!}' in excess. The head is 

 large, with often rather long and filiform antennae, and simple 

 eyes arranged in variously shaped patches near the base of 

 the antennae. 



In Julti* the body is slender and seldom more than three 

 inches long ; the sides of the first scutum are produced in 

 the female, while the antennae are long and filiform. Wood 

 says the males are "farther distinguished b}' a peculiar altera- 

 tion of the first pair of feet, which are transformed into a pair 

 of very large, thick organs," which probably serve as clasping 

 appendages. Julus is found commonly under sticks, etc. It 

 is long, cylindrical, hard, with numerous feet, short and weak, 

 attached to the under surface of the body nearly in the middle 

 of the abdomen. The antennae are short and filiform. They 

 crawl rather slowly, and at rest curve the body into a ring. 

 They live on vegetable substances, or eat dead earth-worms or 

 snails. "In the spring the female deposits her eggs in rnasst- 

 of sixty or seventj*, in a hole excavated for the purpose under 

 the ground ; after three weeks or more the young make their 

 appearance." (Van der Hoeven.) Newport states that when 

 hatched the young Julus consists of eight rings, including the 

 head. The body of the embryo, seen from above, is com- 

 pressed and wedge-shaped, being broadest at the second and 

 third segments. For many days (seventeen) after hatching, 

 the embryo is surrounded by a membrane which Newport re- 



