1910] Diplopoda from the Western States 247 



Anal scutum with four denticiilations along each lateral margin, 

 each of these teeth bearing a stout seta. Dorsal surface with trans- 

 verse rows of setae. Caudal process of the scutum straight, bearing 

 four long, finely pointed setae. 



Ventral plates impressed with the usual transverse furrow and with 

 a less distinct longitudinal one. Smooth except for a moderate cloth- 

 ing of hair. 



Legs rather long and slender, the second article inflated. 



In the male the first two pairs of legs are conspicuously smaller 

 and the ultimate joint is clothed within with stout setae subseriately 

 arranged, the row being more even and well marked on the second. 

 Other legs on inner surface with rows of setigerous tubercles, the setae 

 being short, otherwise with sparse short hair only, except on the proxi- 

 mal articles. Second legs showing a cone-shaped, apically truncate 

 process on the ventral surface of coxa. 



For structure of copulatorv appendages of the male see PI. XXXVII, 

 figs. 2, 3, and 4. 



Length of female, .26 mm. Width, 3 mm. Length of antennae 

 ad 3.8 mm. 



Locality— Kendrick, Idaho (W. M. Mann). 



Polydesmus (Kepolydesmus subgen. nov.) sontus sp. nov. 



Dorsum deep brown to almost black, the prozonites mostly paler; 

 carinae yellow. Pleural region between carinae and the bases of the 

 legs brown. First segment commonly darker than the adjacent ones, 

 often black, the caudal and carinal borders and the minute setigerous 

 granules yellowish. Venter and legs yellow. Head with the vertex 

 dark brown to blackish, the dark area extending forward between the 

 antennae as a narrow, median tongue-like band, the color commonly 

 deeper at the base or proximal end of this band; sides of head dark, a 

 yellow band between dark area of vertex and the sides extending obli- 

 quely forward over insertions of antennae to the yellow lower frontal 

 and clypeal area. Antennae yellow to brown, the sixth and seventh 

 articles commonly conspicuously darker, the seventh being black and the 

 sixth dark brown to black. 



Body gradually attenuated cephalad; over posterior portion with 

 the sides subparallel excepting for the few last segments which are 

 narrowed in the usual way. 



Vertex of the head crossed longitudinally by a fine median im- 

 pressed line which extends almost to an imaginary line tangent to the 

 upper edges of the antennal sockets. Frontal and clypeal region clothed 

 with setose hairs of moderate length, the vertex appearing glabrous or 

 nearly so. 



Antennae short, a little less than or at most equalling the width 

 of the body. Scarcely clavate. Sub-sparsely hirsute, the hairs more 

 dense on the flexed side. 



First dorsal plate in outline semi-circular or half-moon shaped, 

 but the caudal margin a little incurved. Wider than the head inclu- 



