80 The Craspedosomatidae of North America. 



Third legs of male moderately crassate; coxaj i^roduced, third joint much 

 swollen. 



Legs 4-7 not specially modified. 



Genitalia of male of two pairs of laniinse, the anterior broad, the posterior 

 slender. 



Ninth legs of male two-Jointed; basal joint bulbous, attenuate above; second 

 joint broadl}' oval. 



Tenth legs with coxa much enlarged, the other joints reduced. 



Segments of adult 30. 



Distribution : Northeastern North America. 



This genus is named for Dr. L. M. TJnderwood, to whose kind- 

 ness we are indebted for the opportunity of studying Myriapoda. 



The following new species is made the type of the genus be- 

 cause the male is known, and the generic secondary sexual char- 

 acters are drawn from this species. In the other characters the 

 two species agree, except in the proportions of the antennal joints. 



A noteworthy fact regarding this genus is the enormous pre- 

 ponderance of females. We have collected nearl}' 300 specimens, 

 of which but two are males. In most Diplopoda the females are 

 more numerous than the males, but such a proportion as this is 

 not reached elsewhere, as far as we are aware. The other genera 

 of Craspedosomatidfe do not seem to have the sexes especiallj- 

 unequal in number. 



Under wood ia polygaiua sp. n. 



Plate X, figures 180-190. 



Body fusiform, broadest about the middle, narrowed gradually to both 

 ends. 



Vertex prominent, smooth and shining, Avithout evident sulcus. 



Clypeus sparsely hirsute below ; evenly convex. 



Eyes broadly triangular, of 13 ocelli arranged in three rows 6+5+2. Tlie 

 external ocellus of the upper rows is somewhat above the line of those with 

 which it is counted. 



Antennte moderately robust, slightly clavate; the approximate ratios of 

 lengths of joints, beginning with the seventh: 3:4.5:9:5:10:5:3. .Joints all 

 hirsute, the distal more than the jiroximal. 



Mentum rounded in front and behind. 



Promentum triangular, the posterior side concave. 



Stipes and lingual laminaj with a few long hairs. 



Lingual lobes with three sense-cones. 



Styliform processes deei^ly trifid, the middle tooth smallest. 



First segment broadly reniform. the posterior corners rather square; not 

 medianly emarginate behind. Outer setigerous tubercles somewhat mesad 



