1176 General Notes. [ November, 
tera of the families Leptidæ, Bibionide, Xylophagida, Therevide, 
Dolichopodide, Fungicole, Limnobiidz and Tabanida. Thirteen 
ganglia, two cephalic, three thoracic and eight abdominal, is the 
normal number in all the families except the last, but Rhyphus 
(Fungicolz) has the two last abdominal ganglia fused together. 
The Tabanidz have only seven ganglia, one cephalic (no infra- 
cesophagean ganglion), one thoracic and five abdominal, the three 
first distant, the last two approximated. “Thus the nervous sys- 
tem of the larve of Tabanide constitutes an intermediate form 
between the nervous system of the larvae of the Muscidae and 
that of the larvae of the Nemocera and some other families of 
dipterous insects.”.—-—The same naturalist writes upon the ner 
vous system of Stylops meltte and Xenos vesparum (Strepsiptera). 
In the head the ganglion supra-cesophageum only is present, 
thorax has one large ganglion with five nuclei; and the abdomen 
a single oval ganglion connected with the thoracic ganglion bya 
long and thin cord. The thoracic ganglion is divided into two 
parts, the first corresponding to the ganglion infra-cesophageum 
and the first thoracic ganglion of other insects; while perro 
rior and larger part corresponds to the other thoracic ganglia a a 
to some abdominal ganglia. oe 
HYMENORUS RUFIPES AS A MYRMICOPHILOUS spEcies.—What 
we stated on p. 748 of the last volume regarding the es 
the larva of the above-mentioned species has been corre k 
this spring. We have reared the beetle from larvæ foun Z 
Messrs. Th. Pergande and E. A. Schwarz in large paige my : 
nests of Formica fusca in the vicinity of Washington. we ae 
constructs its nest of loose soil, and there are very pga | 
sticks or other vegetable substances in those nests bee oe 
likely to serve as food for the Hymenorus larve, and the T 
habits of the species remain, therefore, a mystery. a ae 
MIGRATION oF PLANT-LICE.—Y ou will perhaps have reer : 
Comptes Rendus that I discovered this year the full cycle ® R 
of Tetraneura rubra migrating from the roots Triinu E al 
the trunks of the elms (Ulmus campestris). Now I ee undated 
for the first leaves to see if the young issuing from the Ie ponding : 
egg give me the Psendogyne fundatrix forming the ae use 
all. I have but little doubt that it will be 50, ™ tirely the 
winged pupifera, obtained at the grass roots, shows pei 
same characters as the emigrant of the galls, an d it also 
day I found the insect at the grass roots I found ! whe 
the elm bark. Kessler writes me that © without, > nig lel 
ies of Aphis 
they go,” he has ascertained this year that s p came back 
the trees, on which he observed them, in June an piconeura tl 
the same in October. The species observed are Sc! y Ape 
Aplus padi, A. evonymi, A. viburni, A. sambuct, fe wise 
and Siphonophora platanoides, —J. Lichtenstein, Montper 
