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PROCEEDINGS OF THE NATIONAL MUSEUM 



minating in a rather prominent rounded depression between the 

 antennae. Two paramedian clypeal setae rather close to the labrum, 

 and a pair of supra-antennal setae on each side of head. Antennae 

 widely separated at base by a distance slightly less than length of 

 2d antenna! article. Antennae long, extending back to front of 3d 

 tergite; 2d, 3d, and 6th articles similar in size and shape, 4th and 

 5th a little shorter. The 7th article hemispherical, with four small 

 terminal sensory cones. Antennae becoming increasingly setose dis- 

 tally, the first two articles almost glabrous. 



CoUum large, considerably wider than the following segment, its 

 lateral ends strongly narrowed and bent cephalomesiad, entirely con- 



FiGURE 6. — Gonopods of Pachydesmus clarus: a, mesial, b, lateral aspect. 



cealing base of mandibles when head is depressed. Surface of collum 

 polished, not becoming coriaceous near the ends. Anterior edge 

 straight, margined up as far as base of mandibles. Posterior edge 

 straight across back, thence abruptly and sinuously swept forward. 

 Paranota of first eight segments directed forward, their corners 

 broadly rounded, those of segments 9-15 transverse, those of last 

 segments becoming increasingly produced caudad. Paranota narrow, 

 less than one-third diameter of body cavity, subhorizontal but tilted 

 cephaloventrad. Tergites of both prozonites and metazonites finely 

 coriaceous, paranotal surfaces slightly more so. Peritreme swollen 

 and polished, not set off by a groove. Anterior edges of paranota 

 strongly margined, the posterior edges acute, not margined, those 

 near the caudal end of body slightly convex, meeting caudal edge 

 of metazonite at a slightly re-entrant angle. Interzonal furrow very 

 distinct across dorsum and finely striate longitudinally. 



