1886. ] Entomology. 69 
name of Palzacridiodea, and divided into three groups with seven, 
mostly new, genera. 
The types-so discovered belong to the three orders of Orthop- 
tera, Neuroptera, and Hemiptera, also to the Heterometabola of 
Packard and of Scudder, while the Metabola are still entirely 
wanting. But of the Heterometabola the Coleoptera are entirely 
wanting. 
Between the Orthoptera and Neuroptera is placed the new order of 
Neurorthoptera, with the sub-order of Neurorthoptera in a special 
sense, and the Palzodictyoptera of Goldenburg; the first of these 
suborders embraces two families, the progenitors of the recent 
Phasmidz, the Protophasmida, with genera containing the colossal 
forms: Protophasma, Lithophasma, Titanophasma and Arche- 
gogryllus, and the Stenaropterida with three genera. 
To the Palzodictyoptera belong the Stenodictyoptera with the 
genera Eugereon Gold., Haplophlebium Scudd., Goldenbergia 
Scudd., Dictyoneura Gold., and two new genera wholly without 
recent representatives; in addition, the Termes-like Hadrobrachy- 
poda, with Miamia Scudd., and the new genus Leptoneura, besides 
the wholly extinct Platypterida provided on the end of the abdo- 
men with two filaments, which belong to the three genera, Lampro- 
ptilia, Zeilleria and Spilatera. 
In the Pseudoneuroptera Brongniart places the wholly extinct 
family of Megasecopterida, with eight new genera whose relatives 
in part bore respiratory appendages on the abdomen, a group to 
which also belongs de Borre’s much-discussed Breyeria borinensis. 
Also a family of Protodonata, regarded as the forerunners of the 
recent Libellulide, with Protagrion n.g. Likewise, thirdly, the 
mily of Homothetida Scudder; also, new families, the forerun- 
ners of the recent ones, viz: the Protephemerina, Protoperlida and 
Protomyrmeleonida. 
Of the Hemiptera five different genera belonging to the Ho- 
moptera have been found, among which belongs, in Brongniart’s 
opinion, Phthanocoris occidentalis, erroneously regarded by Scudder 
as a Heteropteron. 
Belgium. He rejects the mosaic theory of vision proposed by 
Müller, following Exner in his essay on the perception of move- 
ments, and on the theory of compound eyes, presented to the 
Vienna Academy in 1875. 
The work of Exner, says Plateau, leads to the theoretical 
deduction that insects and other Arthropods possessing com- 
pound eyes do not distinguish the form of objects. Exner sup- 
Poses that, in the Articulates and in many other animals, vision 
Operates in a different way from that generally admitted, and 
