with descriptions of several exotic species of Ants. 83 
Odontomachus armatus, Latr. (neuter= Daceton armigerum, 
Perty), Cryptocerus atyatus (female and neuter), Atta cepha- 
lotes (female and neuter), and others, have only eleven jointed 
antenne, the second joint being exposed. No previous au- 
thor has noticed this curious circumstance, and Mr. Shuckard 
stating that ‘this curtailment is never found in the apterous 
social Heterogyna*”, thereon founds an unwarranted rela- 
tionship with the Mutillide. 
The situation of the antennz close to the mouth, and the 
elongated basal joint with the following joint affixed so as to 
form an elbow, are also characters which Typhlopone possesses 
in common with the Ants. 
The mouth is remarkable for the extraordinary minuteness 
of the palpi. The curtailed structure of the trophi (that is, of 
the maxille, labium and palji) is stated by Mr. Shuckard pe- 
culiarly to distinguish the Dorylide from both the Formicide 
and the Muiillide. But this is not the case, as I have in- 
stanced a considerable number of species of ants.in which both 
the maxillary and labial palpi possess much fewer joints 
than the typical number (Introd. 2, p. 219.). 
The structure of the thorax is very interesting in Typhlo- 
pone. Mr. Shuckard has, however, completely mistaken its 
formation, considering the prothoracic collar as the meso- 
thorax, and overlooking the true mesothorax. This has evi- 
dently resulted from the want of a careful examination of the 
corresponding parts in the allied groups, and the absence of 
generalization in the views taken of the thoracic organization ; 
hence, therefore, the erroneous nature of the observations 
which Mr: Shuckard has published relative to the supposed 
peculiar distinction between Typhlopone and the other apte- 
rous Heterogyna of both groups, and of the relation between 
Typhlopone and the Dorylide in this respectt. 
The principle upon which the variation in the development 
of the thoracic segments is regulated, depends entirely upon 
* Mr. Shuckard has made some observations relative to the adoption of 
the term Heterogyna of Latreille, contending that the term ought to be re- 
tained for the Mutillide, instead of being applied to the Ants, as it is by 
Saint Fargeau and Haliday. It appears to me, however, that the term was 
intended to apply either to the distinction which existed between the winged 
females of Formica and the wingless females of Mutilla, or to the difference 
between the winged females and the wingless pseudo-females of Formica. 
In this latter sense the name is the most appropriate that could be applied to 
the Formicide as distinct from every other group of insects. 
+ Amongst other things, Mr. Shuckard states that when the meso- and 
metathorax are of unequal size in the winged males of Heterogyna, it is the 
latter which is most developed,—a statement neither confirmed by nature nor 
by the principle that the segments of the thorax are always in proportion to 
the size of the locomotive organs which they respectively bear. 
a 2 
