THE MYRIAPODA OF NORTH AMERICA. 75 



distinctly 3 or 4 toothed, Last row of scales on posterior segments 

 composed of 6 or 8 setae tipped scales, which project beyond border of 

 segments. Ventral plate of ninth pair of legs not produced as in ser- 

 ratus, copulation foot very similar. Length of body, 15 to 18.5"""; 

 width 2.2 to 2.S'" 11 '. 



Habitat. — Little Rock, Arkadelphia, Okolona, Murfreesboro, and 

 Ultima Thule. 



As already indicated, this species is closely related to serratus. It 

 is principally separated by its smaller size and form of the ventral plate 

 of ninth pair of legs of male. 



This species may only represent a geographical form of serratus. It 

 is very abundant throughout the State, and all those collected during 

 the summer were in the larva stages. I am indebted to Mr. Hutch er- 

 son for adult specimens. 



15. Fontaria virginiensis (Drury). 



Abundant at Donaldson, common at Okolona. 



Specimens from Arkansas are similar to those from North Carolina, 

 but those from northern parts of Mississippi valley represent geograph- 

 ical species. 



At Donaldson the adults were found crawling on the surface of the 

 ground in company with a large number of their young, probably one 

 adult to 500 or 800 young, then (July 11, 1887) about half grown. 



This species seems to be more confined to river bottoms and low 

 rich woodlands. 



The odor of prussic acid is strongly emitted by this species through 

 a series of pores on each side of the body. 



16. Spheeriodesmus pudicus, sp. now 



General color pinkish, especially posteriorly, anterior half of seg- 

 ments darkest, a black median dorsal line, antenna} dark, legs pale. 

 Body widest and highest anteriorly, tapering posteriorly, smooth, seta? 

 absent. Vertex smooth, somewhat sulcata Antenna? subclavate, 

 about equaling width of body. Dorsal plates smooth, four preced- 

 ing the last with an indistinct row of obtuse scales; lateral plates, ex- 

 cept the first, antepenult and penult with their posterior margin serrate. 

 Anal plate triangular with the angles rounded, sparsely pilose. Legs 

 long and slender, extending beyond sides of body. Male : Ventral plate 

 of second pair of legs produced into two short cones; coxa? of second 

 and third pairs more pilose than others; copulation foot much twisted, 

 end expanded and divided, pilose. Length of body 7 n " n ; width 2 mra . 



Habitat. — Little Rock and Okolona. 



This is the first time that any species of this genus has been found 

 in the United States. It is easily distinguished from S. mcxicanus 

 (Saussure), by having a few scales on posterior dorsal plates. 



The collection contains two specimens of this species. 



