124 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



Mating takes place at night on the tree trunks. To endeavor 

 to find where the eggs are laid, about twenty large specimens 

 of both sexes were taken in early May and confined in a deep 

 jar filled with ordinary leaf litter and set in the ground. By 

 the end of July young had appeared in the jar although it had ~ 

 previously been examined without finding eggs. At this time, | 

 however, it was discovered that in most cases the excrement Jgel^ | 

 lets^were not solid but consisted merely of a thin shell surrounding ? 

 a comparatively large cavity in which the small brown-skinned j 't \ I 

 egg was lying loose. 'These pellets showed no external differ- | \ 

 ences from the solid normal pellets cast by large individuals 

 of the species, but when exposed to the air for a few minutes the 

 color changed slightly on account of the more rapid drying out ? ? | I g 



" = 









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of the thin shell. About a pint of both kinds of pellets was 

 placed in tin boxes where they could be frequently examined. 

 By the middle of August most of the young myriopods had 

 devoured their enclosing pellets and were feeding on the solid | \ 

 ones. They measured 8 mm. in length and had seven pairs of 

 legs, but some were moulting into a slightly longer, many-legged jjj | . ~ 3 

 (35 pairs) form. Before the middle of September they had re- | | " 

 duced all of the frass pellets in the tin into a mass of very fine 

 frass and were crawling on its surface seeking other food. They * | \. I 

 congregated on bits of rotten wood that were introduced and s I f | 

 began feeding, but the condition of this rotten wood was appar- 

 ently unsuitable, and a few days later all were found dead on f I | 

 the surface, many having had all their legs eaten off by those \\\\ 

 who survived the longest. ! = l ? 



The writer has been unable to find intermediate sizes between 

 these small (10 mm.) larvae and those of about an inch in length 

 which are found living free, but he has sometimes found rotten | f f 

 logs in a peculiar state of moist, brittle, almost black decom- g f | 

 position in which great numbers of young Spirobolus, one to one ? I i" 

 and a half inches in length, were living, each in its cell and usually ? ? I ; 

 with the remains of one or more cast skins in the same cell. These 

 cells apparently had no external opening and the myriopod was 

 developing by eating away the inner surface of the cell. One 

 such log seen by the writer several years ago had been recently 

 deposited by a freshet on a sand-bar in the river and hundreds 

 of full-grown myriopods were leaving the log and crawling over 

 the sand in all directions away from it. The writer believes 

 that young myriopods enter such rotten wood after freeing them- 

 selves from the egg pellets. 



The very slow rate of growth of the young larvae and the 

 fact that at anytime at least four distinct sizes of immature myri- 



