HYMENOPTERA — FORMICIDZ. 219 
neuters is horny, strongly emarginate, and introduced perpendicularly 
between the mandibles (fig. 85. 13.) ; the mandibles are horny, large» 
and powerful, varying in the sexes as well as in the different species: 
in many they are somewhat spoon-shaped, but obliquely truncate at 
the tip, and multidentate. Such is their character in the females 
(jig. 85. 7.) and neuters (fig. 85. 14.) of F. fusca; but in the males 
of this species they are not toothed, but produced into a terminal 
point (fig. 85.2.). In some males, however, they are also toothed, 
as in the other sex (fig. 86. 13. mand. of Stenamma (W.) Westwoodii 
(Steph. Cat.) ; whilst in the neuters of Typhlopone fulva W. they are 
somewhat sickle-shaped and serrated on the inner edge (fig. 86. 18.). 
In the neuters of others they are very long, linear, and deflexed at the 
tip.* In Myrmecina, they are said by Curtis to be wanting in the 
males. The maxillee are coriaceous, small, and terminated by a broad, 
rounded, thin lobe, which defends the sides of the labium; the max- 
illary palpi vary in the number of their joints from six to two. In 
Myrmica and Formica they are 6-jointed and of considerable length, 
scarcely varying in the sexes (fig. 85.3. max. 3, 85.8. max. 9, 85. 15. 
max. ? F. fusca). In Atta and Cryptocerus they are scarcely as 
long as the maxilla, and 5-jointed (Hist. N. Fourm. p. 33.). In Po- 
lyergus and Ponera there are five or four joints, and in Myrmecina La- 
treillei and Stenamma Westwoodii, four (jig. 86. 14.). In Pheidole 
providens Westw. ( Atta p. Sykes, Trans. Ent. Soc. vol.i. pl. 13. f. 5.), 
and Typhlopone fulva W. (fig. 86. 19.), I have only been able to 
detect two joints in the maxillary palpi. The mentum is small, 
corneous, and cup-shaped; the labium membranous and rounded, but 
often, especially in dried specimens, it shrinks into the mentum. In 
the three kinds of individuals of F. fusca (jig. 85. 4. labium ¢, 
85.9. @, 85.16. >), there is no material difference in these parts, 
nor in the labial palpi, which in that genus are 4-jointed : in Polyergus 
rufescens, Myrmecina Latreillei, and Stenamma Westwoodii, they are 
3-jointed (fig. 86. 15.) ; whilst in Atta cephalotes, Pheidole providens, 
* From the important share which these organs take in performing the duties of 
the individuals, especially of the neuters, it is evident that their various forms 
imply a diversity of habits with which we are, however, unfortunately, in many 
cases ignorant: thus, in Polyergus, which does not labour, but compels the species 
which it has made its slaves to perform its work, the mandibles are slender and 
destitute of teeth; and Latreille mentions two kinds of neuters in Eciton hamata, 
with different shaped mandibles, adding — “ forte horum neutrorum officia pariter 
diversa.” (Gen. Crust. &c. vol. iv. p. 129.) 
