1910] Diplopoda from the Western States 245 



Antennae elavate. Moderately to sub-sparsely clothed with 

 mostly short hairs. 



First dorsal plate less in width than either head or second dorsal 

 scutum but relatively wider than in granulatus. Somewhat semicir- 

 cular in outline but at each side extended into a narrow carina which is 

 dentate, there being commonly two major teeth of which the caudal 

 has a minor or secondary denticle on its posterior edge and in front of 

 the anterior of which are several small denticles. Front margin mesally 

 sub-straight, laterally convexly rounded. 



Depressed along the cephalic margin, the depression extending- 

 caudad mesally and narrowing to a furrow which again expands trian- 

 gularly adjacent to the caudal margin. The segment elsewhere ele- 

 vated. Densely covered with tubercles, the setae much as in gran- 

 ulatus. 



Second segment with the lateral ends curved cephalad and embrac- 

 ing the first. Segment longer laterally than mesally. Bearing three 

 transverse rows of large tubercles. Carinae with cephalic angles acute 

 but caudally widely rounded; laterally showing eight or nine rather 

 small crenulations, the incision between them shallow; no translucent 

 margin such as is present in granulatus. 



Subsequent segments gradually increasing in length and showing 

 from three to five or six transverse rows of tubercles. Posterior angles, 

 of carinae becoming less widely rounded and extending farther and 

 more acutely caudad, in the last few segments being a little produced. 

 Lateral margins of carinae with small crenulations or teeth which for 

 the most part are well rounded and not at all acute; teeth or crenula- 

 tions numbering from eight to ten or twelve, the lesser number occur- 

 ring on the spiraculiferous segments. Prozonites very finely and densely 

 granulate. 



Anal plate convexly elevated proximally, bearing separated rows 

 of conically pointed tubercles; two tubercles projecting laterad at 

 base or proximal end of the cylindrical apical portion of scutum, this 

 portion being slightly depressed ventrad and apically rounded and bear- 

 ing on caudal surface four setigerous tubercles. 



Anal valves with mesal and caudal margins elevated and smooth. 

 In some an irregularly oblong area over posterior portion of each valve 

 roughened with sharply separated depressed areolae. A setigerous 

 tubercle in furrow near caudo-mesal angle and a second similar one 

 near middle of plate nearer mesal than dorsal margin. 



Anal scale with caudal extension convexly rounded and bearing 

 two setigerous tubercles. Lateral portions in outline something like 

 that of the fore part of a shoe. 



Length 12-13 mm. Width ad 2 mm. 



Locality — Upper branches of Mill Creek Canyon, Utah. 



A number of specimens were obtained about springs in 

 upper side branches of the canyon. It seems to be close to 

 S. granulatus though clearly distinguishable in numerous 

 details. 



