324 Prof. 0. Hcer on the House Ant of Madeira. 



Latr. [Formica pusilla, De Geer, from South America), it agrees 

 in size, colour, and the armed thorax ; but in that, the thorax, 

 with the head, is shagreened with numerous little raised points, 

 which is not the case in our species. In the form and size of the 

 head, the soldier of the CEcophthorn agrees with the Atta mega- 

 cephalo, Latr. (from the Isle of France) ; yet Latreille would 

 surely not have overlooked the peculiar striated sculpture of the 

 head : but since neither the description nor figure gives this, 

 we cannot identify our species with his; and this especially as 

 the female is said to be only a little larger than the neuters, — 

 the difference in ours being so considerable. From this, A. 

 megacephala, Latr., the ant so called by Losana (Memorie della 

 Reale Accademia di Torino, xxxvii. p. 328), is distinct; and the 

 description of the species which is found in the gardens of 

 Piedmont agrees in all points of importance with the soldier of 

 the Madeiran ant. On the other hand, the description of the 

 labourer is quite inapplicable, for it assigns to it a larger heart- 

 shaped head. It is also very surprising that Losana should not 

 have remarked that the head of the labourer is quite smooth, 

 and that labourers and soldiers present constant differences, not 

 only in size, but also in the formation of the head. 



1. The Female. 



PI. III. fig. I. 1, the natural size; fig. i. 2, ten times magni- 

 fied ; fig. I. 3, in profile. 



Whole length 3^ lines. Length of the head | line, breadth 

 the same. Length of the thorax 1 line, breadth | line. Length 

 of the abdomen 1| line, breadth nearly 1 line. Length of the 

 upper wings 3^ lines, breadth Ij'j line. 



The head is roundish, and of the breadth of the thorax, as 

 long as broad, with a very slight notch at the base behind. 

 The eyes are rather small, and composed of few lenses. The 

 three ocelli are very distinct, and placed at the base of the 

 head in a triangle. The clypeus is not distinct from the 

 forehead ; slightly hollowed out directly over the mouth, where 

 the edge is furnished wdth a row of punctures. The anten- 

 nary clefts are somewhat converging forwards, short, but broad 

 and deep, and rather widening forwards, where the forehead, 

 which otherwise is fiat, becomes more prominent. The 

 forehead between the antennary clefts is moderately broad, 

 and furnished at its anterior margin with an impressed, tri- 

 angular, somewhat smoother compartment, which is faintly 

 keeled down the middle. The whole upper side of the head 

 is traversed by fine parallel strife longitudinally, which reach 

 down nearly to the base of the head ; behind the eyes the stride 

 are fainter, more irregular, and partly obsolete, or passing into 



