The Crasjyedosomatidae of North America. 57 



tain, however, maii}^ statements which we look upon as of doubt- 

 ful import or questionable truth, and such are given in italics, our 

 reasons for doubt being stated later on. 



" Body very long and slender, not fusiform ; consisting of thirty segments 

 besides the head, with about fifty-tivo 2Mirs of legs, unth the penultimate joint very 

 long. Head rather large, and nntisually broad ; no eyes present ; the gense 

 TinusTially large, but not so globose as in Trichopetakim ; the front is also car- 

 ried farther up on the vertex than usual, and is much broader than long; the 

 clypeus flat, slightly bilobed on the front edge. The antennae are moderately 

 long and hairy, with the sixth segment scarcely longer than in Trichopetalum, 

 but more uniform in thickness, scarcely longer than thick; the terminal joint 

 as long as the sixth, the end conical, more produced than in Trichopetalum 

 or Zjfgonopus; at the tip are four rather long seuse-setse. Body segments be- 

 coming as usual smaller next to the head ; the anterior of each division of the 

 arthromere much swollen high up on the sides; each shoulder with three 

 tubercles, which are arranged in a scalene triangle and bearing much longer 

 setae than in the other genera, though not quite so long as the body is thick. 

 The legs are long and slender, more so than in Trichopetalum, and somewhat 

 more than in Zygonopus. Tn the male the eighth pair of legs are rudimen- 

 tary, being two-jointed, the second joint only one-fourth longer than the basal, 

 and ending in a well-developed stout claw. The genital armature minute and 

 very rudimentary, pale, scarcelj^ chitinous; the outer lamina short and thick, 

 with a stout external recurved spine, and two terminal obtuse points; the 

 inner lamina shorter, forming a truncated angular spine, and not much more 

 than half as long as the outer lamina; between the inner and outer lamina, 

 its base next to the inner lamina is a middle spine ending in an irregular tuft 

 of fine spinules. 



"This genus is distinguished from Trichopetalum by its want of eyes, its 

 broader head, its long slender body, with long setfe, by the eighth pair of female 

 rudimentary legs ending in a claw. From Zygonopus it differs in the shorter 

 sixth antennal joint ; its broader head ; its slenderer legs, the sixth pair in the 

 female not being unlike the others, and by the more prominent shoulders and 

 longer sette. The species of the (;wo genera are of the same general form and 

 size. ' ' 



"About 20^ and 9 examined. Body white, with no dusky discolorations; 

 30 segments behind the head in specimens 11 mm. in length and 5^ pairs of 

 legs ; in one female individual 8 mm. long there were 49 pairs of legs, includ- 

 ing the eighth or rudimentary pair ; in another individual 6 mm. long there 

 are 24 segments behind the head. The head is provided with short, fine erect 

 hairs of different lengths, especially on the sides of the gente." 



" Males and females are alike in size and form." 



That the bodj'^ is " not fusiform," but that the segments be- 

 come, " as usual smaller next to the head," seem to us mutually 

 contradictor}^ statements. In all the Chordeumidse known to us 

 the last joint of the legs is longest, not the penultimate, though 



