446 bulletin: museum of comparative zoology. 



Mesonotum pyriform, flattened behind, with a feeble transverse im- 

 pression at middle and a longitudinal impression in front, the sides 

 slightly margined posteriorly. Epinotum in profile rather flat above; 

 its base about twice as long as declivity, into which it passes at a broad 

 rounded angle; surface of base broadly concave, that of declivity 

 flat; base of declivity with broad, ear-shaped tubercles. Petiole one 

 and a half times length of postpetiole, without antero ventral tooth; 

 the node in profile as deep as broad, concave in front, rounded behind, 

 with a constriction near apex. Postpetiole broader than petiolar 

 node, rounded above, the anterior surface nearly straight; antero- 

 ventral border angulate in front, but without distinct tubercle or 

 tooth. Legs long and slender. 



Gaster shining, sparsely, regularly punctate; rest of body and the 

 legs subopaque. Head and thorax rugulosely punctulate, a median, 

 longitudinal surface on the front less so and more shining than the 

 rest; front of head between frontal carinae and eye concentrically 

 striolate. Mandibles shining, coarsely striate. Epinotum and petio- 

 lar node transversely striolate; postpetiole rugulose like the front 

 of head. Body and legs everywhere with abundant erect hairs. 

 Mandibles, funiculus, and antennal scapes with semierect hairs, last 

 four funicular joints pubescent. 



Color light ferruginous, pile and pubescence yellow. 



Female (dealated). Length 6.5 mm. 



Closely resembling the worker. The white ocelli are small, but 

 distinct. The smooth surface on the front is shorter but more dis- 

 tinctly shining than in the woi'ker. 



Described from a single female and several workers found at Porto 

 Velho. This species is near M. iheringi Forel, from which it differs 

 in its larger size, the head more constricted behind, in the much 

 larger size of the eye, and in the subopacity of the tegument, which in 

 M. iheringi is shining. 



in. Tranopelta gilva Mayr. var. albida, var. nov. 



Several workers of a small variety of Tranopelta gilva Mayr were 

 taken at Camp 39, Madeira-Mamore R. R. These differ from 

 var. brunnea Forel, the only form of which the worker is known, in 

 the smaller size (length L5 mm.) and in the uniformly pale color 

 which in the series before me is almost white, with a faint tinge of 

 yellow. 



