AET. 18 



NEW GENERA OF MILLIPEDS — COOK AND LOOMIS 



9 



Antennae crassate, rather strongly clavate, joints 5 and 6 distinctly 

 thicker than the others ; joint 6 about twice as long as joint 5 ; joints 

 2 and 4 subequal, distinctly exceeded by joint 5 ; joint 7 distinctly pro- 

 jecting; a large, orange-yellow transversely-oval sense organ near 

 the rim of joint 5 on the lateral face. In crawling the antennae are 

 carried directly forward. 



Fig. 1. — SiPHONACMB lyttoni. a. Lateral tibw of head. 6. Antenna of 



FEMALE, VENTRAL VIEW. C. GONOPODSj VENTRAL VIEW 



First segment large, subelliptic, the anterior margin transverse or 

 with a slight angular emargination ; a transverse crescentic area in 

 front of the middle of the segment slightly depressed or less convex 

 than the surface behind it, forming a thin collar over the base of 

 the head. 



Segments rather strongly convex ; the surface of the posterior divi- 

 sion tuberculate and pilose, the hairs inserted between the tubercles, 

 the posterior margin minutely and regularly serrate, supplementary 

 margin not apparent; anterior subsegments beset with circular or 

 oval flattened or broadly rounded tubercles like those of the posterior 

 subsegments, but usually without hairs or with only a few near the 

 posterior subsegment; pleural sutures at the lateral margins of the 

 segments, the dorsal plates scarcely projecting beyond the pleurae. 



Last two segments longer than any of the preceding, without legs 

 or ventral plates; last segment with the pleural and ventral sutures 

 completely fused; penultimate segment with the sutures open. 



Last segment distinctly longer than the penultimate, gradually 

 narrowed at the sides and rather broadly rounded at the apex; pre- 

 anal scale distinct, the margin transverse, nearly straight; anal 

 valves prominent, evenly convex, somewhat exceeding the posterior 

 margin of the segment, the surface pilose but not distinctly sculptured. 



58237—28 2, 



