The Graspedosomatidae of North Ainerica. 25 



posed face may be smooth or roughened, plane or with a longitudinal carina. 

 On the 12th legs of males of some species the apex projects antero-ventrally 

 as a large conic process. 



First two pairs of legs G-jointed, the others 7-jointed, by the intercalation 

 of a very short joint just beyond the coxa. 



As the species here described have usually been placed under 

 the Lysiopetalidse by American students of this group, it ma^^ 

 not be superfluous to notice a few considerations regarding the 

 systematic importance of the characters on which this family is 

 based. 



The Family Chordeumidse was erected in ISiT by C. L. Koch, 

 his entire characterization being : " Der Korper standhaft mit SO 

 JRingen,^^ and this would be sufficient, as far as known, to distin- 

 guish the European species among Chilognatha. Mature individ- 

 uals of certain small species of lulidse sometimes occur with as low 

 as 30 segments, but in no lulus is the number of segments con- 

 stant. We have, however, in America at least four species of 

 Craspedosomatidse with less than 30 segments in the mature con- 

 dition, a fact which might seem to militate against the validity 

 of the famil}^ 



The number of segments, however, though appearing to be a 

 character of considerable value on account of its supposed con- 

 stancy, is by no means the most important of the numerous 

 differences between this and other families. The more import- 

 ant distinctions have been neglected entirely or passed with a 

 mere mention because of the easy statement of which the above 

 apparently sufficient character was capable. In many respects 

 the Chordeumidse are evidently the highest of the helminthomor- 

 phous Diplopoda, if not of the whole group. 



In the first place, the head is proportionally much larger than 

 in any other diplopod family. Instead of being enclosed or cov- 

 ered by the first segment, this last structure forms a sort of neck, 

 fitting' into the posterior concavity of the head, and allawing a 

 much freer motion for that member than is possible for other 

 Diplopoda. All the organs connected with the head are in a 

 comparatively high state of development. The eyes, antennae and 

 mandibles are all capable of more effective service than the cor- 

 responding structures of other families. 



The legs are proportionally longer and the animals capable of 

 faster locomotion. This fact is correlated with the absence of re- 



