1911] Wheeler — Netv Ants from Mexico and Central America 205 



to be an allied form but although the head resembles that of Ph. 

 tisiphone in outline, the sculpture is very different and the length 

 of the body is only 3 mm. 



Macromischa laevissima sp. nov. 



Worker. Length 1.6 mm. 



Head, excluding the mandibles, nearly as broad as long, with feebly convex sides, 

 rounded posterior corners and convex posterior border. Mandibles convex, with 

 two large apical and 3 or 4 minute, indistinct basal teeth. Eyes rather large, con- 

 vex, situated a little in front of the middle of the head. Clypeus, convex, with 

 romided, entire anterior border and a median longitudinal impression bounded on 

 •each side by a narrow, rather distinct ridge. Frontal area obsolete. Frontal car- 

 inse short, feeble and parallel. Antennae rather slender; scapes reaching to the pos- 

 terior border of the head; funicle with a 3-jointed club as long as the remainder of 

 the funicle; its first joint fully as long as joints 2-4 together; joints 2 and 8 as long 

 as broad, joints 3-7 a little broader than long, joints 9 and 10 together shorter than 

 the terminal joint. Thorax narrower and a little longer than the head with the 

 mandibles, from above somewhat broader in front than behind, with rounded humeri, 

 in profile evenly rounded dorsally, without sutures or constrictions; epinotum de- 

 pressed and sloping, without distinct base and declivity, armed with two rather 

 long, slender, acute spines, which are directed backward and outward and slightly 

 upward, closely approximated at their bases and with their tips very slightly de- 

 flected. Petiole with a long, slender peduncle and an erect node at its posterior 

 end. This node is nearly as high as the length of the peduncle, strongly compressed 

 anteroposteriorly with rounded upper border and flat anterior and posterior sur- 

 faces, the former passing over rather abruptly into the horizontal dorsal surface of 

 the peduncle. Postpetiole from above a little broader than the petiole, broader 

 than long, subrectangular, nearly as broad in front as behind; in profile its node is 

 convex though much lower than the node of the petiole. Gaster elliptical, with 

 broadly excised anterior margin and feebly convex sides and dorsal surface. Legs 

 rather long; middle and hind femora incrassated. 



Surface very smooth and shining; mandibles, sides of clypeus and cheeks finely 

 and sharply striated; surface of head, thorax and gaster with much scattered, 

 minute piligerous punctures. 



Hairs white, very short, erect and scattered, obtuse on the body, slender, pointed 

 and appressed on the legs and antennal scapes. 



Black; mandibles, antennae, petiole and postpetiole dark brown; tibiae and tarsi, 

 brownish yellow. 



Described from a single specimen taken by Prof. A. Petrunke- 

 witch at La Buena Ventura, near Santa Rosa, Vera Cruz, Mexico. 



M. Icevissima is the smallest known species of the genus. It is 

 closely related to the Texan M. suhditiva Wheeler and goes down 

 to it in my table of Macromischa (Bull. iVmer. Mus. Nat. Hist. 



