250 Journal New York Entomological Society. [\'o!. xix. 



surface and these acute and prominent. Length 2.8-3.5 mrn. Guatemala 



and British Honduras intermedia Forel. 



Median prothoracic spines short, blunt and usually bifid, much shorter 

 than the lateral pair ; mesonotum with two unequal pairs of spines, the 

 anterior pair often reduced to mere tubercles ; petiole less than i H times 

 as long as broad ; tubercles on the dorsum of the first gastric segment 

 (except in saussui-ei) more numerous and less prominent 13 



13. Larger species (3.5-5 mm.) with robust spines and prominent tubercles; 

 mesonotum in front with two pairs of spines, the anterior small and 



tuberculiform 14 



Smaller species (2.5-4 mm.) with more slender spines and less prominent 

 tubercles ; mesonotum in front with a single multifid blunt spine or 

 projection 15 



15. Sides of head rather straight and subparallel ; tubercles on gaster dense 

 and numerous ; epinotal spines stouter, directed backward : color ferru- 

 ginous red ; hairs on legs coarse and erect. Arizona, .arizonensis Wheeler. 

 Sides of head convex ; tubercles on gaster larger, sparser and fewer in 

 number ; epinotal spines more slender, directed upward ; color yellowish 

 brown ; hairs on legs less coarse, reclinate. Mexico saussiirei Forel. 



15. Color brownish yellow; surface of body rather smooth, slightly shining.. 16 

 Color ferruginous ; surface of body opaque and granular 17 



16. Only the front, vertex, a median spot on the postpetiole and a median 



longitudinal stripe on the first gastric segment black. New Jersey. 



septentvionalis McCook (typical). 

 Dark markings on the head and gaster more extensive and in addition a 

 dark median longitudinal band on the thorax. New Jersey. 



septentrionalis var. vertebrata var. nov. 



17. Surface of body not covered with gray granules or glistening particles. 



Texas septentrionalis subsp. obscurior Wheeler (typical). 



Surface of body covered with gray granules or glistening particles 18 



18. Body covered with glistening particles. Texas. 



septentrionalis obscurior var. crystallina var. nov. 

 Body covered with small gray granules 19 



19. Thoracic spines small and slender. Texas. 



septentrionalis obscurior var. irrorata var. nov. 

 Thoracic spines longer and more robust ; sculpture coarser. Florida. 



septentrionalis obscurior var. seminolc var. nov. 



In my paper on the North American fungus-growing ants I de- 

 scribed the habits of the typical T. obscurior of Austin, Texas, and 

 gave measurements and figures of its nests. Mr. Hartman has sent 

 me all his notes on several colonies of the varieties irrorata and 

 crystallina. Although he did not distinguish between these varieties 

 in the field, it is probable that they do not difYer appreciably in habits 



