Il6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. Ill 



row of 6 to 9 unpaired setae, 4 to 7 long. Sometimes i minute seta 

 at posterior end of longitudinal branch of impression. Laterotergite I 

 extending length of segment ; bearing 4 to 6 setae. Spiracles usually 

 slightly larger in first abdominal segment, situated in anterior half of 

 segment, in extreme posterior part of subovate spiracular sclerite, 

 which is slightly wider than spiracle and considerably longer. Pleu- 

 rite well developed, subovate, somewhat diminishing in size from 

 first to eighth segment, with 2 or 3 setae. Sternum of i sclerite, 

 subquadrate ; impressions very faint, 2 lateral impressions sometimes 

 appearing as pale membranous lines ; with about 10 fine setae around 

 margins. 



Ninth abdominal segment (fig. 23, g), exclusive of urogomphi, 

 about as long as eighth abdominal segment and three-fourths as 

 wide; four-fifths as long as wide; tapering caudally, making width 

 at anterior margin of caudal notch about two-thirds greatest width 

 of segment. Dorsum convex anteriorly, flattened posteriorly; sloping 

 downward from front to back. Dorsal plate (dpla) irregularly 

 wrinkled; 4 faint longitudinal impressions, a paramedian pair (pirn) 

 which converge posteriorly, but do not meet, and 2 laterally (lim) 

 which are very indefinite ; sometimes with a shallow round depression 

 near center ; typically with 4 setae in central area, but highly vari- 

 able ; lateral margins slightly raised and carinate, bearing 3 prominent, 

 blunt setiferous tubercles or "teeth" (to) ; transverse impression 

 (trim) continuing completely across segment. Tergite continues un- 

 interruptedly laterally and on posterior ventral surface; usually with 

 from 10 to 15 unpaired setae on each side, some issuing from small 

 sclerotized tubercles; anteriorly on lateral aspect i or more trans- 

 verse rows of shallow pits or rugae, usually bearing minute setae. 

 Distance between posterior margin of pleural area and anterior margin 

 of caudal notch approximates one-sixth total length of segment (ex- 

 clusive of urogomphi). Pleural area large, transversely striated. 

 Sternum of 2 sclerites, separated anteriorly by medium suture and 

 posteriorly by tenth abdominal segment; each sclerite with 6 to 8 

 setae, mostly in row around tenth abdominal segment. 



Urogomphi (ur, fig. 23, g; fig. 23, e) separate, bifid, projecting 

 dorsocaudad; outer prong (opr) larger than inner prong. Inner 

 prong (ipr) small, projected mediocaudad and sometimes slightly 

 dorsad, terminating in sharp, upturned tip; i long seta from lateral 

 aspect and i or 2 setae ventrally near base. Outer prong (opr) about 

 twice as large as inner prong, corniform, projecting upward with 

 sharp tip curving forward and slightly inward ; 2 long setae, i from 

 lateral aspect of distal half of prong and i from strongly margined 



