88 bulletin: museum of comparative zoology. 



Worker. Length 3.5 mm. 



Head much smaller than in the soldier, as broad as long, rather rectangular, 

 with straight posterior boi'der and feebly convex sides. Eyes small, but very 

 convex, hemispherical, distinctly behind the middle of the head. Mandibles 

 large, shaped somewhat as in the soldier, but with much less convex external 

 borders, with 2 or 3 apical and several minute, widely spaced basal teeth. 

 Clypeus moderately convex, with nearly straight anterior border. Frontal 

 area large, flat, triangular. Antennal scrobes short, limited to a groove for 

 the base of the scapes between the prominent rugae. Antennal scapes straight, 

 not flattened at the base, extending about ^ their length beyond the posterior 

 corners of the head. Funiculi also longer than in the soldier, with all the 

 joints longer than broad. Thorax shaped much as in the soldier, but the 

 pronotum with a pair of very long, straight, pointed spines, directed upward 

 and outward, distinctly longer than the similarly directed spines on the epino- 

 tum. The latter, however, are bent slightly backwards at a feeble angle just 

 beyond the middle. Shape of petiole, postpetiole, and gaster much as in the 

 soldier, but the spines on the petiole are less spreading and more erect, more 

 slender, and acute. 



Sculpture of thorax like that of the soldier; mandibles and clypeus smooth, 

 the anterior border of the latter with short, coarse rugae, the head very coarsely 

 longitudinally rugose, the rugae connected by transverse rugules. Antennal 

 scrobes shining, feebly punctate, transversely rugulose anteriorly. Petiole 

 postpetiole and gaster smooth and shining. 



Pilosity and color much like those of the soldier, except that the mandibles 

 are more yellowish and without dark borders. 



Described from a single soldier and two workers taken by Mr. John 

 Hewdtt at Kuehing. 



This species seems to be very close to A. for ox Emery, based on a 

 worker specimen from Perak. I am, however, unable to make Emery's 

 description of the sculpture of the head and thorax accord mth that of 

 the Bornean form. At any rate his words " f oveolis piligeris confertis 

 sculptum" do not seem to me to describe the conditions in my speci- 

 mens. Moreover, he gives the length of his specimen as about 4.5 mm. 

 and describes the two pairs of thoracic spines as equal (" thorax spinis 

 cjuatuor subrectis, aequalibus armatus"), and the postpetiole as 

 " sublaevis," whereas it is very smooth and shining in dyak. The ants 

 of the genus Acanthomyrmex seem to be very rare. No one has taken 

 A. notahilis since it was described by Smith, and Bingham in the 

 Fauna of British India merely translates Emery's description of A. 

 luciolae of Ceylon. Emery has recently based another species, A. 

 kochi, from New' Guinea (Nova Guinea, 9, Zool., 1911, 2, p. 252) on a 



