62 PROCEEDINGS OP THE NATIONAL MUSEUM vol. 08 



Measurements. — 



Length of entire soldier (to tip of mandibles) 6.80 mm. 



Length of entire soldier (to central point), 2.40 mm. 



Length of head with mandibles, 3.10 mm. 



Length of head (to tip of central point), 2.35 mm. 



Length of head without mandibles (to tip of labrum). 2.35-2.40 mm. 



Length of head without mandibles (to anterior), 2.00 mm. 



Length of central spine, 0.45 mm. 



Length of left mandible, 1.70 mm. 



Length of pronotum, 0.30 mm. 



Length of hind tibia, 1.00 mm. 



Width of head (at posterior), 1.25-1.35 mm. 



Width of pronotum, 0.75 mm. 



Lighter colored and with the two lateral points slightly more 

 robust and the central point less robust than in a soldier of M. {S.) 

 brevicornutus from Coxipo, Cuyaba; head and central point longer 

 than in rohustus Snyder; head narrower than that of trispinosus 



FIG. 2. CONTRASTING DORSAL. VIEWS OF THREEI FRONTAL PBOCESSES ON HEADS OF SOLDIERS 



OF THREE AMERICAN SFINITERMES ; NOTE THAT THE PROCESSES ARE SLIGHTLY ASYM- 

 METRICAL a. SOLDIER OF MIUOTERMES (SFINITEHMES) ROBUSTDS SNYDER. (IXIAMAS. 

 BOLIVIA, DECE.MBER, 1921.) 6. SOUJIER OF MIROTERMES (SFINITERMES) BREVICORNUTUS 

 HOLMGREN. (ROSARIO, BOLIVIA, NOVEMBER, 1921.) C. SOLDIER OF MIROTERMES (SFINI- 

 TERMES) TKISPINOUS HAGEN. (CACHUBLA ESPERANZA, BENI RIVER, BOLIVIA, MARCH, 

 1922.) (FIGS. 3a, b, AND C CAMERA LUCIDA, ALL DRAWN TO THE SAME SCALE) 



Hagen (pi. 2, figs. 3 and 6), and head and central point longer (com- 

 pared with type) (fig. 2c) ; head wider than in nigrostomus Holm- 

 gren; mandibles larger than in gracilis Holmgren — where the an- 

 terior middle of the labrum is concave. 



Described from two soldiers collected with workers at Rosario, 

 Bolivia, in November, 1921, by W. M. Mann (No. 5). These sol- 

 diers may represent a new species which is close to S. hrevicoi^nutus 

 Holmgren. 



MIROTERMES (SFINITERMES) ROBUSTUS, new species 



Soldier (fig. 2(7). — Head yellow-brown, darker anteriorly, robust, 

 narrowed toward anterior margin, three elongate and robust blunt 

 points at anterior margin, the two lateral points are elongate and 

 approach the central point in size as in M. (S.) trispinosus Hagen; 

 the central point forms an acute angle with the head; head with 

 sparse short hairs and a few longer hairs, anterior points with dense 

 long hairs. 



