Prof. 0. Heer on the House Ant of Madeira, 325 



dots. The upper lip (labrum) (fig. i. 4) is very small, and de- 

 pends quite perpendicularly between the mandibles ; it consists 

 of two horny plates, a very short but broad basal piece, and a 

 second longer outer piece, which is rounded, and slightly notched 

 anteriorly ; in the middle of the notch stands a little papilla. 

 The labrum is beset with a double row of fine bristles, one 

 within the other upon the edge, with two longer, stouter bristles 

 in the centre of the lip. The mandibles (fig. i. 5) are very 

 strong and horny, becoming broader and hatchet- shaped ex- 

 ternally; the fore-edge exactly truncate, and produced for- 

 wards into a strong tooth, furnished with a narrow horny rim 

 or border extending at the top into a short, not prominent, tooth. 

 This border, which, as the actual cutting-edge, forms the man- 

 dibles, is very sharp, but without teeth. The outer edge of the 

 mandible is grooved ; the upper surface, on the contrary, even. 

 The maxilla is much smaller. The peduncle (stipes) is perga- 

 mentaceous, narrowed at the base, notched at the top, to which is 

 affixed the extremely small two-jointed palpus : this is so small, 

 that it does not reach to the point of the sheath. The first joint 

 is cylindric, the second somewhat longer, fusiform, and produced 

 into a fine point. The sheath extends pretty far out beyond 

 the stipes; it consists of a stalk-like basal piece (fig. iii. 5. b^) 

 and a larger membranous very thin upper piece, which is rounded 

 at top and furnished with a crown of hairs; further below 

 the hairs cease, and the edge is naked and extremely thin ; but 

 here a border of excessively minute hairs runs obliquely over 

 the surface of the sheath. The labium is very small, as 

 long as the stipes of the maxilla, greatly narrowed at the base, 

 broader outwards and bluntly rounded. The lingual palpi are 

 two-jointed and very short ; the first joint obconic, the second 

 fusiform and somewhat longer, bearing two bristles. The men- 

 tum is corneous, and slightly hollowed out. The antennae are 

 moderately long; the first joint (the scape) extends a little beyond 

 the edge of the head, and is scarcely perceptibly thickened out- 

 wards : the flagellum is eleven-jointed; its first joint is about twice 

 as long as the next very short one ; all are of equal thickness ; 

 the three last are considerably larger, though not abruptly di- 

 stinct from the rest ; they are together about the length of the 

 seven preceding joints. All the joints of the flagellum are finely 

 hairy, especially the last three. 



The thorax is pretty large. The prothorax is very short, and 

 not perceptible from above; laterally, however, the side-piece 

 (PL III. fig. I. 3 a^) forms a pretty broad prominent segment ; 

 the mesothorax composes the chief part of the thorax (fig. i. 3 Z>) ; 

 the mesonotum is somewhat larger than the head, rather flat 

 above, nearly circular, but truncate behind, with a transverse 

 impression and row of impressed punctures, and on either side a 



