wheeler: ants of the genus opisthopsis. 361 



Bismarck Archipelago: Ralum (Fr. Dahl). 



I have not seen this species, which Forel described from two speci- 

 mens so badly damaged that he could not determine the form of the 

 thorax. According to Dahl, it nests in rotten portions of tree-trunks. 

 It seems to be rather closely related to the following species. 



17. Opisthopsis manni, sp. nov. 

 Plate 3, fig. 25, 26. 



Worker. Length 3-4.5 mm. 



Smaller than the preceding species. Head long, with straight, 

 anteriorly converging sides, straight posterior border and large, 

 prominent eyes. Mandibles 5-toothed, with rather convex external 

 borders. Clypeus broader than long, subcarinate. Thorax shaped 

 much as in 0. haddoni, the base and declivity of the epinotum subequal, 

 the former straight and horizontal, the latter abruptly sloping and 

 concave, the angle between very distinct but slightly rounded. Peti- 

 olar scale apparently a little thicker than in most species of the genus, 

 its superior border not so high as the epinotal angle, straight and trans- 

 verse in the middle. Gaster and legs of the usual shape. 



Smooth and shining, not distinctly shagreened, the head and mandi- 

 bles slightly more opaque than the thorax and gaster, the mandibles 

 with fine, scattered and indistinct punctures. 



Hairs sparse, yellow, erect and rather short, absent on the thorax 

 and petiole. Pubescence absent. 



Clear orange-yellow; cheeks, clypeus, and mandibles paler and more 

 lemon-yellow; anal segment, last tarsal joint and funiculi, with the 

 exception of the first joint, black. Palpi yellowish. Eyes pearl-gray. 



Female (dealated). Length 6.5 mm. 



Very similar to the worker; head a little broader, broader than the 

 elongate elliptical thorax. Petiolar scale with entire, rounded superior 

 border. 



Sculpture, pilosity, and color as in the worker, except that the scutel- 

 lum is black. 



Described from several workers and a female from Malapaina 

 (type-locality) and several workers from Malaita and Yandina, 

 British Solomon Islands. These specimens were recently taken by 

 Dr. W. M. Mann, who writes me as follows concerning their habits: 

 " The only note I have on the Malapaina specimens of Opisthopsis is 

 that they were nesting beneath bark in a depression on the trunk of a 



