8 PKOCEEDINGS OF THE NATIONAL MUSEUM vol. 68 



Abdomen straw-yellow, with dense long hairs at base tergites, 

 cerci prominent. 

 Measurements {major soldier) . — 



Length of entire soldier, 4.10 mm. 



Length of head with mandibles, 1.75 mm. 



Length of head without mandibles (to anterior), 1.05 mm. 



Length of left mandible (base mandibles), O.SO mm. 



Length of labrum, O.GO mm. 



Length of pronotum, 0.35 mm. 



Length of hind tibia, 0.85 mm. 



Width of head (at widest point), 1.10 mm. 



Width of labrum (at apex), 0.20 mm. 



Width of labrum (at base), 0.22 mm. 



Width (average) of labrum (at center), 0.20 mm. 



Width of pronotum, 0.70 mm. 



R. latildbrum Snyder has a broader head, and mandibles have 

 longer, more robust and differently located teeth than in longilahius 

 Emerson, as well as a broader labrum and longer and broader 

 pronotum. The antennae have 16 segments Avhereas in longidens 

 Snyder the antennae have only 15 segments, the labrum is broader 

 at the apex than in longidens^ and the posterior margin of the pro- 

 notum more emarginate. 



Soldier, minor (pi. 1, fig. 9). — Head straw-yellow, margins and 

 rim of antennal socket darker, labrum yellow-brown, broadest at 

 posterior of antennal socket, sides slope gradually and roundedly 

 to posterior margin, where rounded, conical at apex; head and 

 labrum convex in profile; head with three rows of long hairs. 

 Labrum elongate, slender, broadest at apex, with one long hair 

 and dense short hairs on each fork at the apex. Mandibles yellow- 

 brown, long, straight, slender, and sharp pointed (taper towards 

 apex) , nearly as long as one half the length of the labrum. 



Antenna light yellow-brown, 14 segments, with long hairs; third 

 segment subclavate, longer than second or fourth; fourth beadlike, 

 shorter than second segment; segments become longer and broader 

 toward apex ; last segment conical. 



Pronotum straw-yellow, darker on margins, saddle-shaped, an- 

 terior margin not sharply turned up, narrowed and rounded; pro- 

 notum raised up (convex in profile) at middle, sides roundedly slope 

 to posterior margin which is slightly roundedly emarginate; a few 

 long and short hairs on the margins. 



Legs white with tinge of yellow, slender and with long hairs. 



iVbdomen light straw-yellow, with roAv of long hairs near base of 

 each tergite, cerci prominent. 



Measurements (minor soldier^) . — 

 Length of entire soldier, 2.90-3.15 mm. 

 Length of head with lal)rum, 1.25 mm. 

 Length of head without labrum (to anterior), 0.55 mm. 

 Length of labrum (to base of frontal gland), 0.63 mm. 



