THE MYRIAPODA OF NORTH AMERICA. 191 



third of posterior half of segment. Anal segment obtuse, not pro- 

 jecting beyond valves; anal valves more strongly compressed than in 

 brandti, densely punctate, especially above; anal scale slightly an gu- 

 lated. Legs short, not quite extending beyond sides of body. Seg- 

 ments 54-59. Length 50-55 ,nm ; width, 4-4.3 mm . 



This species is described from two specimens which I found amongst 

 a large number of. 8. surinamensis without any locality ; but as there 

 was another vial of surinamensis labelled "Surinam" I am inclined to 

 believe that this species is from the same locality. 8. vulvanus Karsch, 

 the only other American species having the repugnatorial pore on the 

 posterior half of segment, has 3+3 or 4+4 clypeal foveolae. 



2. Spirobolus c a Hi pus, sp. iiov. 



Diagnosis. — Related to Spirobolus brevicollis Voges, but the clypeal 

 foveohe 3+3 or 4+3; segments 43-47; $ coxae of 3, 4, 5, 6 pairs of legs 

 produced; tarsae without a polster. 



Habitat. — Guanajuato, Mexico; Duges. 



Type. — Male and female, U. S. Nat. Museum. 



Description. — Male and female. Ochraceous, posterior border of seg- 

 ments dark; antennae and legs brown, joints ringed with white. Ro" 

 bust, anterior segments scarcely attenuated. Vertex moderately smooth, 

 sparsely punctate and very slightly reticulated, sulcus short, not very 

 shallow; clypeus transversely wrinkled, not very deeply excised, 

 foveohe 3+3 or 3+4, sulcus large, extending to opposite base of autennae. 

 Antennae almost filiform, not extending beyond second segment ; that 

 of the female slightly shorter. Ocelli 30-36 in 5 or 6 series; patch sub- 

 triangular. Segments not striate or wrinkled above, but densely punc- 

 tate; posterior part beneath with almost straight striae, those on an- 

 terior part more oblique, forming an obtuse rounded angle in connection 

 with those on posterior part. Sides of first segment subacute, no striae 

 except marginal; anterior border sabexcised. Repugnatorial pore 

 small, touching sulcus, which is bent forwards; behind pore on pos- 

 terior part a deep sulcus. Anal segment subacute, not extending be- 

 yond anal valves; anal valves moderately margined, punctate; anal 

 scale large, obtusely angled. Legs short, not extending beyond sides 

 of body. Segments female, 43 ; male, 47. 



Male less robust than female; coxae of 3, 4, 5, 6 pairs of legs produced, 

 that of third largest and curved backward, the rest short; coxae of 

 second pair large; tarsi without a pad or other markings. Copulation 

 foot very different from that of brevicollis, resembling that of S. ameri- 

 cw-borealis ; ventral plate obtusely angled, one-half as high as foot; 

 inner part of anterior foot pointed and covered with numerous short, 

 round truncate tubercles, outer part with its end curved outwards, not 

 tuberculate; posterior foot hook-like, pointed, its anterior surface 

 tuberculate. Length, 58 mm ; width, 6.5 mra . 



