80 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. Ill 



from transverse branch to posterior transverse row of setae and in 

 some cases nearly the whole distance. Anterior part of mediotergite 

 without row of setae. Posteriorly on each mediotergite, transverse 

 row of 4 to 6 prominent unpaired setae and usually i to 3 short, fine 

 setae placed between some of larger hairs. One prominent seta and 

 sometimes also i small seta on margin of mediotergite laterad to 

 impression. Laterotergite I extending length of segment; with 3 

 setae. Spiracles subequal; about in middle of segment just ventrad 

 to most anterior seta on lateral aspect of mediotergite. Spiracular 

 sclerite pale, subovate, wider than spiracle and 2 to 4 times as long. 

 Pleurite (pi, fig. 18, c) large, subovate with i large and sometimes 

 also I small seta near center. Sternum (st) subquadrate; in first 5 

 segments laterosternites (Ist) separated off by well-defined sutures 

 which are usually closed in sixth to eighth segments, sutures some- 

 times slightly open on sixth segment; usually about 6 unpaired setae 

 around margin of sternum. 



Ninth abdominal segment (fig. 18, g), exclusive of urogomphi, 

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

 nearly as long as wide ; posterior half tapering caudally, making width 

 at anterior margin of caudal notch from three-fifths to two-thirds 

 greatest width of segment. Dorsum slightly convex anteriorly, flat- 

 tened posteriorly; sloping downward from front to back. Dorsal 

 plate (dpla) irregularly lined and wrinkled; sparsely punctulate; 2 

 faint irregular impressions laterally; paramedian impressions incon- 

 spicuous and indefinite, sometimes meeting in a small, shallow, central, 

 ovate depression ; without setae except at lateral margins, which are 

 raised and carinate, bearing 3 blunt "teeth," each with a long bristle ; 

 transverse impression (trim) continues completely across segment. 

 Tergite continues uninterruptedly laterally and on posterior ventral 

 surface ; usually with from 7 to 9 setae on each side, some issuing from 

 small sclerotized tubercles; segment slightly expanded anteriorly on 

 lateral aspects, usually with a few faint pits. Distance between pos- 

 terior margin of pleural area and anterior margin of caudal notch 

 approximates one-fifth of total length of segment (exclusive of uro- 

 gomphi). Pleural area large, consisting of transversely striated mem- 

 brane except for small ovate pleurite at anterior ends. Sternum of 2 

 sclerites, separated anteriorly by median longitudinal suture and 

 posteriorly by tenth abdominal segment; each sclerite usually with 

 3 or 4 prominent setae and a few small setae, mostly in row around 

 tenth abdominal segment. 



Urogomphi {ur, fig. 18, g; fig. 18, /) separate, bifid, projecting 

 dorsocaudad ; prongs subequal. Inner prong (ipr) projected caudad, 



