22 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.64, 



3. Eyes very large (long diameter 1.15 mm.); median vein nearer to cubitus. 



magnoculus, new species. 

 Eyes not very large (long diameter 0.95 mm.); median vein equally distant from 



subcosta and cubitus grandis Rambur. 



Eyes small; median vein nearer to cubitus 4. 



4. Antennae with 19-20 segments, entire length 32-34 mm.; long diameter of eye 



0.58 mm territus Emerson. '^ 



Antennae with 19 segments, entire length 29 mm.; long diameter of eye 0.59 mm. 



parallelus Silvestri. 



5. Antennae with 21 segments obtusus Holmgren. 



Antennae with 20 segments 6. 



6. Larger species, entire length 34.5^0 mm peruanus Holmgren. 



Smaller species entire length 30 mm ., long diameter of eye 0.70 mm., ocelli separated 



from eye by distance equal to over half the eye diameter; median vein nearer to 



Bubcosta (Lassance, Peru) manuscript species of Emerson. 



Still smaller species entire length 28 mm., long diameter of eye 0.75 mm., ocelli 

 separated from eye by a distance equal to one-half eye diameter, median vein 

 nearer to cubitus molestus Burmeister. 



KEY TO FIFTEEN SPECIES OF THE GENUS SYSTERMES HOLMGREN. 



Soldiers. 



1. Thoracic nota with long, sharp lateral spines, frontal tube projecting 2. 



Thoracic nota without long, sharp lateral spines, three-coinered ; sides produced 



to blunt points, frontal tube nearly flat (not raised up), small species 11. 



2. Mandibles with prominent marginal teeth 3. 



Mandibles with marginal teeth not prominent 10. 



3. Lateral spines of meso- and metanota usually very robust, more or less conical; 



large and robust species, total length 14-22 mm 4. 



Lateral spines of meso- and metanota relatively short, more or less cylindrical. . 9. 



4. Mandibles relatively slender beyond marginal teeth 5. 



Mandibles relatively not slender beyond marginal teeth 8. 



5. Head markedly hairy, many long hairs at base mandibles, meso- and meta- 



thoracic spines long and droop markedly toward posterior 6. 



Head not markedly hairy, thoracic spines relatively short 7. 



6. 15 mm. in length, left mandible with marginal tooth not projecting much if any 



beyond inner margin of mandible dims Burmeister. 



20 mm. in length, left mandible with marginal tooth projecting, snyderi Emerson. 



7. Pronotum not wide, mandibles not markedly incurved near apex, left mandible 



with marginal tooth near apex of labrum, 14-19 mm. in length, tibia, 5-f mm. 



in length grandis Rambur. 



Pronotum relatively wider, mandibles markedly incurved near apex, left man- 

 dible with marginal tooth beyond apex of labrum, 15.5-i- mm. in length. 



magnoculus, new species. 



8. Head hairy, mandibles robust (not slendei), relatively short, marginal tooth on 



right mandible not near base, base of mandibles with many long hairs, 15-17 



mm. in length, tibia 5-1- mm. in length chaquimayensis Holmgren. 



Head with few hairs, marginal tooth on right mandible near base opposite small 

 basal tooth on left mandible, but few long hairs on base mandibles, 17-H mm. 

 in length, tibia 6.75 mm. in length emersoni, new species. 



9. Sides of head nearly parallel-oval, only slightly narrowed anteriorly, length of head 



with mandibles 8.5-9 mm., entire length 13.5 mm hageni Holmgren. 



Head broader, shorter and strongly narrowed anteriorly, length of head with 

 mandibles 7-10 mm., entire length 15-17 mm peruanus Holmgren. 



18 The characters of this termite S. territus Emerson MS. are those used by Alfred Emerson in his descrip- 

 tion and the species should be cr< dited to Emerson. 



