238 , ENTOMOLOGICAL SOCIETY 
knowledge of the biology of this genus has not advanced a single step 
beyond the results obtained by Mullen In fact, no one has hitherto been 
able to rediscover the pupa skin. 
For nearly thirty years afterwards only the captures of various insects 
among ants were recorded by various authors, but in 1841 and 1844 Mr. 
Fred. Mserkel. of Saxony, published (Germar's Zeitschr. f Ent. , vols. 
iii and v) the first comprehensive work on myrmecophilous insects. He 
raised the number of these insects to 284, distributed as follows among the 
different orders: Coleoptera, 274; Orthoptera, i; Heteroptera, 3; Ily- 
menoptera, 2 ; Diptera, 4 (among them a then unknown larva, which 
afterwards proved to be that of Merodon). In the same year (1844) Schi- 
oedte added quite a number of species belonging to various orders, and 
numerous additions in Coleoptera were made in 1846 by Prof. Mseklin. 
In the latest catalogue of myrmecophilous insects, Mr. E. Andre (Revue 
et Mag. Zool., 1874) enumerates no less than 584 species, among them 542 
Coleoptera, but of these more than 250 must be considered as more or less 
accidental visitors of ants' nests. 
Mserkel proposed to arrange myrmecophilous insects in three groups : 
ist, species which live among ants only in the larva and pupa stages, but 
which, as images, leave the company of ants (e. g., Euryomia, Coscinop- 
tcra, etc.j; 2d, species which in the imago state are often met with 
among ants, but often also at other places not in company of ants (the 
numerous accidental visitors) ; 3d, species which in the imago state (and 
presumably also as larva) are exclusively found in the nests of ants, and 
the existence of which appears to depend upon the ants (the true myrme- 
cophilous insects). 
He excludes certain Membracida and Aphididce which, properly speak- 
ing, do not live among ants of their free will, but are carried into the nests 
by the ants and held in captivity. These would constitute a fourth class, 
and later discoveries added thereto certain species of Formicidce, which 
are kept as slaves by other species of ants. A fifth class would be formed 
by the true parasites of ants, viz., certain Diptera (probably Conopida}, 
Hymenoptera (Chalcidida and Proctotrupidfe), and Coleoptera (Stylopi- 
dce}, 
In more recent times important contributions have been made to our 
knowledge of the biology of myrmecophilous insects and their relations to 
the ants mainly by the investigations of von Hagens, Lespes, Sir John 
Lubbock, A. Forel, E. Andre, and E. Wasmann. These investigations are, 
of course, connected with great difficulties. If we uncover from beneath a 
stone or a log a colony of ants, or if we dig into a large ant-hill, the in- 
habitants are at once put into the greatest uproar, and no observations can 
be made. To closely observe the domestic life of the ants and their inqui- 
lines it is necessary to construct artificial formicaries in suitable glass 
jars, as described by Sir John Lubbock. Among the authors just men- 
tioned, Mr. Wasmann has, since the year 1886, reviewed the previous rec- 
ords and augmented the same by a long series of the most interesting 
