12. Formica scrutator. F. nigerrima, mandibulis tarsorumque articulo apicali pallidè ferrugineis, thorace medio profundè coarctato.
Worker. Length 1½—2 lines. Shining black; the mandibles pale, ferruginous, with their inner margins finely denticulate; the eyes placed rather forwards on the sides of the head, the latter emarginate behind. Thorax deeply strangulated in the middle; the metathorax elevated and obliquely truncate behind. Abdomen ovate; the scale of the petiole sub-incrassate, with its margin rounded above; the insect very thinly covered with a fine cinereous pile.
13. Formica angulata. F. nigra nitida; flagello capite anticè pedibusque obscurè ferrugineis, metathorace angulato.
Worker. Length 3 lines. Shining black; head of moderate size; the clypeus and mandibles obscure ferruginous; the flagellum fusco-ferruginous, with the tip pale testaceous. Thorax rounded anteriorly and compressed behind; the scutellum prominent, forming a small tubercle; the metathorax obliquely truncate, the margin of the truncation elevated, so that when viewed sideways the metathorax forms an obtuse angular shape. Abdomen ovate, the node of the peduncle elevated, incrassate, rounded anteriorly, and flat behind.
Hab. Aru.
Gen. Polyrhachis, Smith.
1. Formica sericata, Guér. Voy. Coq. Zool. ii. 203; Atlas Ins. pl. 8. f. 2, 2 a, b, c, d, ☿. (Polyrhachis sericata, Smith, Append. Cat. Form. p. 200.)
Hab. Aru; New Hebrides.
2. Formica sexspinosa, Latr. Hist. Nat. Fourm. p. 126, pl. iv. f. 21 ☿. (Polyrhachis sexspinosa, Smith, Cat. Form. p. 56. 3.)