MYRIAPODA 63 



shortness of the interlocking parts of the segments, but the segments 

 of the Polyzoniidae are already extremely short, and the relative flexi- 

 bility of the body in the vertical plane is evidently greater in Hypo- 

 zonium than in the much thicker Polyzonium. 



An even more striking difference between Polyzonium and Hypo- 

 zonium exists in the fact that the last segment, which in Polyzonium 

 is distinctly visible from above as a narrow projection, is in Hypo- 

 zonium entirely concealed and greatly exceeded by the large trapezoidal 

 penultimate segment. In Polyzonium the penultimate segment is 

 slightly longer, and of the same shape as the others, but in Hypo- 

 zonium it is over three times the normal length, and is not emargi- 

 nate behind, but broadly rounded. The last segment is very minute 

 and is concealed in a recess between the oblique and rather prominent 

 pleurae of the penultimate segment. 



HYPOZONIUM ANURUM sp. nov. 



(pi. V, figs. la-id.) 



Type. No. 791, U. S. Nat. Museum. Collected at Seattle, Wash- 

 ington, by C. V. Piper. 



Length about 7 mm. ; width 2.5 mm. ; 30 segments. 



Color in alcohol a deep brownish-orange, closer examination shows 

 that the tint is not uniform, but is darker and somewhat mottled on the 

 posterior subsegments. 



The antennae are dark, with a purplish tinge. In form they are ex- 

 tremely robust, more so than in Polyzonium, and much more so than 

 in Platyzonium. The joints are more unequal in size than in Poly- 

 zonium; basal joint short, the sixth much the largest, and the seventh 

 reduced to a stopper-like disk which fits into the end of the sixth and 

 is not visible from the side. 



Eye-spots farther apart than in Polyzonium; ocelli three on each side, 

 in a somewhat obliquely vertical row, the upper farther apart than the 

 lower, but not in a direction so divergent as those of Polyzonium. 

 The upper ocellus is concealed under the margin of the first segment. 



The lateral margins and posterior corners of the segments are much 

 more prominent and rounded than in Polyzonizim, where the sides of 

 the body are a nearly even, continuous line. 



Order Anocheta. 



Cylindrical Diplopoda, mostly of large size. They differ from all 

 except the Colobognatha in having legs on all the anterior segments, 



