10 PEOCEEDINGS OF THE NATIONAL MUSEUM vol. 68 



Wings gray-brown, costal veins golden-brown. In forewing me- 

 dian vein parallel and close to cubital vein, branches and reaches 

 apex of wing in both wings, connected with subcosta by numerous 

 slanting branches; subcosta with a few branches near apex in both 

 wings; cubitus occupies most of the wing area, does not reach apex, 

 with many branches to lower margin of wing. In hind w^ing 

 median parallel and close to cubitus, branches and reaches apex 

 of wing, more distant from subcosta than in forewing, cubitus does 

 not reach apex of wing, with many branches to lower margin of 

 wing. 



Legs yellow, slender, elongate, with long hairs. 



Abdomen yellow-brown (golden brown), paler ventrally, Avith 

 dense long hairs; traces of styli present, cerci fairly elongate. 



Measurements. — 



Length of entire winged adnlt, 18.00 mm. 



Length of entire deJilated adult, 10.05 mm. 



Length of head, 2.40 mm. 



Length of horn, 0.70 mm. 



Length of pronotum, 1.40 mm. 



Length of hind tibiae, 3.00 mm. 



Lengtli of forewing, 13.05 mm. 



Diameter of eye, 0.G2 mm. 



Width of head (at eyes), 2.35 mm. 



Width of pronotum, 2.10 mm. 



Width of forewing, 3.50 mm. 



Described from a single male winged adult collected by W. M. 

 Mann with major and minor soldiers at Cachuela Esperanza (Beni 

 River), Bolivia, in March, 1922. The winged adult of R. 7nanni 

 Snyder is larger and lighter colored than R. niarginalis Linnaeus 

 and has a larger, differently shaped head and longer, broader horn 

 than R. taurus Desneux, but is otherwise very close to taurus; nasuttis 

 Pert}'' should replace taurus. 



Soldier, major (pi. 1, fig. 5). — Head yellow-brown, flat, longer than 

 broad, broadest posteriorly, with scattered long hairs. Fontanelle 

 small with a groove leading from opening to labrum. Labrum 

 yellow-brown, tongue-shaped, as broad as long, with a median 

 groove, tip w^hite, fleshy, broadly rounded, with short hairs. Mandi- 

 bles black with castaneous-brown (reddish tinge) bases, bowed, with 

 slender incurved tips; left mandible Avith two sharp marginal teeth 

 near middle, first (upper) larger than second (loAver) ; right mandi- 

 ble with upper tooth near middle, not prominent, parallel to rim, 

 lower tooth prominent, sharp, near base. 



Antenna yelloAv-brown, bead-like, 18 segments, pubescent; second 

 segment short, cylindrical; third segment elongate, subclavate, as 

 long as fourth and fifth segments together; fourth and fifth seg- 



