A ^lonogrwph of Scytonotus. 241 



Habitat: Among leaves and rotting debris in moist decidu- 

 ous Avoods of Eastern North America. Penns3'lvania (Saj- ) ; re- 

 ported b^- Dr. Wood from Pennsylvania, Michigan and Canada; 

 Mr. Bollman records it as abundant in Indiana. The writers 

 have collected specimens in the following places : S^-racuse, N. 

 Y., and several places in the vicinit\^ Tully, Marcellus, James- 

 ville, Clyde and Wolcott, Wa^aie county, N. Y. ; Lebanon, Pa.; 

 Washington, D. C.,and on the Virginia side of the Potomac near 

 Washington. 



The species is seldom abundant, but in the right locations a 

 few specimens are usually to be found. At Lebanon, Pa., a large 

 number of individuals were found among rotting leaves piled up 

 during high water near a brook. About a hundred specimens 

 form the basis of the present stud3\ The proportions of the 

 sexes seem to be about equal. 



Larval form: Six-legged larvie (fig. 70) of this species were 

 found near Wolcott, Wajnie county, N. Y., in May of the pres- 

 ent 3'ear, among leaves on a wooded hill-side. They are sluggish 

 in their movements and might be mistaken for Lipurge. In color 

 they are pure white. Like the larva of Polydesmus in the six- 

 legged conditions they have seven segments, with a repugnatorial 

 pore on the fifth. The first pair of legs is apparently attached 

 to the first segment. The legs seem to be six-jointed, as in the 

 adults, but the antenna have only four^ joints. There are four 

 olfactory cones (also agreeing with Polydesmus^), and are pro- 

 portionally longer than in the adult. The third joint has on one 

 side a single marginal row of the finger-like sense-organs found 

 on the sixth joint of the adult. The fourth joint has the transpar- 

 ent cones and long hair of the seventh joint of the adult. This 



^ The antennae of the Helminthomorpha have, in reality, eight joints, 

 although nearly always reckoned as seven-jointed, the terminal being 

 reduced to a cap or disk bearing the four olfactory cones. Sometimes 

 this is reti'acted into the end of the seventh joint. In the larva under 

 examination the terminal is not so rudimentary as it afterward becomes. 

 From Rath's diagram (Beitrsege zur Kenntniss der Chilogathen, pi. 3, 

 fig. 24; it appears that this is to an even greater extent the case with 

 the European Polydesmus complanaius. 



^Heathcote (Philos. Trans. Royal Soc, London (1888), pi. 27, fig. 3) 

 figures the antenn;e of a six-legged lulus terrestris as 7-jointed (8 joints 

 with the terminal)and two olfactory cones. This difference is certainly 

 noteworthy if the figures referred to prove correct. 



