1912] Chilopods and Diplopods 169 
Vertex crossed by a deeply impressed sulcus which ends abruptly | 
in a very short transverse line above dorsal margin of the dark transverse 
band. Head clothed with intermixed long and short setose hairs which 
are densest over frontal and clypeal region. 
First dorsal plate a little wider than head inclusive of mandibles. 
Anterior margin weakly convex, meeting the lateral margin on each 
side at an obtusely rounded angle, the anterior and lateral margins 
together roughly hemispherical; anterior and lateral borders trans- 
parent, distinctly margined. Each lateral margin obtusely incised at a 
point about one-third the distance from the caudo-lateral angle to the 
antero-lateral, but no teeth present. Caudal margin concave mesally 
and convex at each side, bow-shaped. Depressed longitudinally each 
side of median portion which appears elevated, more especially so 
caudad. 
Second dorsal plate with lateral portions moderately bent cephalad 
touching or a little overlapped by the first plate. An acute tooth at 
antero-lateral angle; a little caudad of this a lower, very obtuse denticu- 
lation and half way between this and the caudal angle a third very weak 
or obscure denticulation. A broad longitudinal depression or furrow 
on each side somewhat less than half the distance from middle to lateral 
margin of plate. Tubercular areas very weakly developed, plate 
being nearly smooth. 
Third plate very similar to the second but the lateral margins a 
little shorter. Caudo-lateral corner sub-rectangular, a little obtuse. 
Lateral teeth as on the second. 
Fourth plate with lateral margin much longer than that of second 
and third plates. First and second denticulations smaller; antero- 
lateral angle well rounded. 
Subsequent dorsal plates similar to the fourth. All with the lateral 
longitudinal depression as described for the second. Transverse sulcus 
weak. Distinctly margined caudally and laterally and along free 
portion anteriorly. The lateral denticulations very small; a fourth 
weak denticle appearing on some plates caudad of the third. Caudo- 
lateral angles becoming in posterior segments moderately produced 
caudad. 
Anal scutum with process obtusely founded and bearing long sete. 
Dorsally with conical setigerous tubercles. 
Anal valves broad, rounded laterally and caudally. Margined 
mesally and also caudally and laterally, the lateral margin wide. 
Anal scale roughly triangular, the anterior margin convex, the 
caudo-lateral sides very weakly convex, meeting at middle line in an 
acute angle. 
Ventral plates with longitudinal and transverse sulci well developed. 
Legs of moderate length; bristles densest distad; ultimate joint 
densely and subseriately setose ventrally. 
First and second legs in male oe reduced, the second pair a 
little larger than the first. 
For structure of gonopods of male see Pl. X, fig. 3. 
Length 19-20 mm.; width 2.2 mm. 
Locality: Madison, Washington. (Dr. E. Bergroth). 
