720 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.xxi. 



iiieut and uarrower, and does not appear on the first segment — that is, 

 the raised margin is not specially thickened laterad ; posterior corners 

 of carime thick, rounded, subrectaugular to the middle segments, 

 behind which they are slightly and gradually more produced. 



Repugnatorial pores 13, located in distinct excavations behind the 

 middle of the posterior subsegments. 



Preanal scale subsemicircular, the setiferous tubercles smaller and 

 not equaling the distinct apiculus. 



Sterna without transverse ridges. 



Sternum of sixth segment of male with a broad, rounded, apiculate 

 process. 



Sternum of fifteenth segment unmodified. 



Legs of males scarcely crassate; dorsal face of second joint rather 

 slightly iiitiatedf legs 1 to 6 with a very small fleshy sole at aj)ex, their 

 claws not greatly reduced. 



Coxte of second male legs produced into a long, stout papilla, of 

 which the posterior t\ice is flattened and contains the seminal aperture. 



Copulatory legs strongly decurved and with large nodes, as in the 

 large genera Astrodesmus and AulodestmiS', the mesial spine at the base 

 of the flagellum is very long; the flagella are rather stout, strougly 

 flexuous, cross each other, and aie accommodated in a large cavity 

 considerably in front of the aperture in which the copulatory legs are 

 inserted. The anterior edge of this aperture is produced ventrad 

 into a prominent rim, not noticed in other genera. 



SPHENODESMUS RUGULOSUS Cook. 

 (Plate LIX, tigs, la-lc.) 

 Sphenodesmus rngulosus Cook, Proc. U. S. Nat. Mus., 1895, XVIII, p. 83. 



Vertex without hairs, polished and shining ; sulcus distinct, not deep ; 

 as also the inte^antenual suture. 



Clypeus smooth and evenly convex, a curved transverse row of about 

 six minute setiferous punctations below. 



Antennie sparsely hirsute with short hairs, more numerous on the 

 distal joints. 



First segment subelliptic, more regular in outline than in the larger 

 forms of the present family; dorsally smooth and even, the carina? dis- 

 tinctly and equally margined, the margin more distinct laterad, not 

 abruptly, so that a marginal callus, as it appears on the other segments 

 and on other genera, may be said to be wanting; dorsally the carinte 

 are distinctly concave and rngulose; the margins do not extend more 

 than halfway to the median line. 



Second segment with a distinct lateral side, the anterior corner 

 somewhat prominent. 



Segments dorsally smooth, finely coriaceous, or sparsely punctulate 

 in the middle; laterad and on the cariniie distinctly rngulose; posterior 

 segments are also rugulose along their posterior margin. 



