50 PROCEEDINGS OF THE NATIONAL, MUSEUM. yol. 61. 



APTEROSTIGMA ABDITA. new species. 



Worker. — Length, '^ mm. (fig. 22). 



Head, excluding mandibles, nearly one and one-half times as long 

 as broad, with nearly straight, snbparallel sides, and broadly rounded 

 occipital corners ; posterior portion suddenly contracted into a short 

 neck which has a distinctly reflected border. Front with a rather 

 strong impression, bordered by the frontal carinae. Clypeus much 

 broader than long, anterior border feebly rounded. Frontal lobes 

 large and thick, with a strong impression between. Mandibles with 

 a series of twelve teeth, the apical two largest. Antennae stout, 

 their scapes surpassing the occipital corners by about one- fourth 

 their length; first funicular joint a little longer than the second and 

 third joints together; joints 2-10 very slightly broader than long; 

 penultimate joint distinctly broader than long; terminal joint about 

 as long as the four joints preceding. Eyes convex, situated posterior 

 to middle of sides. Pro-mesothorax strongl}'^ convex in profile ; an- 

 terior border elevated into a low, thick ridge. Mesonotum with a 

 pair of rather indistinct, thick, longitudinal ridges. Base of epino- 



tum feebly convex, longer than 

 the flat declivity and broadly 

 I'ounding into it. Epinotal stig- 

 mata prominent. Petiole from 

 above more than twice as long 

 Fig. 22.— APTEROSTIGMA ABDITA. THORAX as broad, widest behind and 



AND TETIOLK OF WORKER. t n • , ii 



gradually narrowing to the 

 stigmata; posterior third with a pair of short and blunt ridges; 

 in profile the node is low and rounded, with rather abrupt, 

 nearly straight posterior slope. Postpetiole a little broader than 

 long, broadest behind, the slightly convex sides gradually converg- 

 ing anteriorly ; posterior border very feebly excised and the dorsum 

 indistinctly impressed. Gaster short and elliptical, the first seg- 

 ment margined at sides by an obtuse ridge. 



Mandibles ver}'^ finely and denseW striate and shining; antennul 

 funiculi feebly shining; head and body opaque, finely and densely, 

 somewhat granulosely punctate ; legs punctate similar to body. 



Pilosity abundant, on the head and body long and flexuous, on the 

 legs and scapes shorter, curved and subappressed. On the legs and 

 scapes there are also some longer hairs, similar to those on the body. 



Color brown. 



Female. — (dealated). Length 4 mm, 



Pro-mesonotum strongl}^ convex in profile. Scutellum rather flat; 

 posterior border concave at middle, with broad, obtuse teeth laterally. 

 Epinotal base and declivity not distinct from each other, margined at 

 sides, the margin obtuseh^ angulate at middle. The rest as in worker, 

 with the usual sexual differences. 



