NO. 1170. THE FAMILY GOMPHODESMID^—COOK. 683 



Anal valves with strougly elevated raargius; two setigerous piiucta- 

 tioiis, tbe superior marginal, the inferior submarginal. 



Preanal scale semielliptic, a broad, rounded, setigerous prominence 

 on eacli side of tbe middle, wliicb is not produced, but ratber truncate. 



Sterna broad and densely hirsute, except the first and last. 



Sternum of tbe fifth segment of male with two large papilliform hir- 

 sute processes between the second pair of legs. 



Sternum of segment C with two similar processes between tbe ante- 

 rior pair of legs. 



Sterna of post genital segments of male with a stout, sbai'ii, conical 

 spine at the base of each leg, more pronounced on posterior segments 

 and larger between the posterior pair of legs of eacb segment. 



Sternum of segment 15 not different from its neighbors. 



Legs of male crassate, hirsute, with long bristles, the joints in order 

 of length 3, 2, 4, 5, 6, 1. 



Second legs of male with the coxai produced ventrad into a rounded- 

 conic, somewhat recurved process; genital opening on the median face 

 of the coxa, at the base of the process. 



Seventh pair of legs with a broadly conic process on tbe apex of the 

 inflated coxa, directed mesocephalad. 



Pregenital legs of male with the distal joint supplemented at apex by 

 a cushion-like process as long as tbe very slender claw. 



Two distal joints of male legs roughened on the ventral face by 

 pai^illiform tubercles, very large on post-genital legs. 



Male genitalia with a broad basal joint; second joint incurved at 

 base, ungual portion subequal in length with tbe other, slender, 

 straight, bifid at apex. 



In this genus the first segment is much more rounded laterally than 

 in ^sfro(7<'swws, being without an apjjareut angle; the whole segment 

 is more convex, making the ends more decurved ; it is narrower in com- 

 parison with the second segment. It is, furthermore, not subemargi- 

 nate toward tbe ends, as in Astrodesmus. 



The greater convexity is shared by the entire body, which has the 

 dorsum more arched and the carinjB more depressed than in Astrodesmus. 



MARPTODESMUS CHANLERI Cook. 



(Plate LV, figs. 2a-2j.) 



Marptodesmus chanleri Cook, Proc. U.S. Nat. Mus., 1895, XVIII, p. 95, pi. iv, figs. 

 1-10. 



•Vertex smooth and shining, sulcus transversely rugulose, not deeply; 

 postantennal depression subvertically rugulose near the lateral margin. 

 Clypeus smooth and shining; a sharp, oblique depression parallel to 

 the lateral margin, halfway between tbe margin and the antennal 

 sockets; below, a few scattering bristles, gradually longer; supralabral 

 bristles long and very numerous, a crowded row next the margin, other- 

 wise without apparent arrangement. 



