PSOCIDiE — ODONATA. 
435 
follows: — Psocus subfasciatus = Peripsocus albiguttatus, Dalm. ; Ps. 
obscurus is a Peripsocus ; Ps. conspurcatus = Ps. A-maculatus^ Lat. ; Ps. 
lucifugus is probably the larva or nymph of a Psocus or Ccecilius ; Ps. pedi- 
cularius = Psyllipsocus ramburi, Selys. Twenty-one species are 
enumerated as found in Belgium. 
Perlid^. 
Gerstacker, Festschr. nat. Fr. 1873, pp. 60-74, pL, figs. 17-33, 
minutely details the characters of the genus Pteronarcys, especially with 
regard to the exceptional external respiratory organs, and describes a 
new species under the name of P. frigida (p. 65, figs. 28 & 29) from 
Labrador. He also describes and figures a second genus from Chili 
(Diamjihipnoa, p. 62) with an analogous respiratory system (the species is 
named D. lichenalis, p. 64, fig. 17). In Pteronarcys, according to Newport, 
and his observations are confirmed by Gerstacker, there are 13 pairs of 
external breathing organs, viz., 5 pairs on the prosternum, 3 on the 
mesosternum and metasternum respectively, and 2 on the basal ventral 
abdominal segments; whereas, in Diamphipnoa the thoracic pairs are 
absent, but there are 4 abdominal pairs. The two genera are also 
abundantly distinct in neuration, &c. [Z>. lichenalis is apparently iden- 
tical with the previously described Stenoperla annulata, Brauer {cf. Zool. 
Rec. vi. p. 452), but the genus Diamphipnoa should stand.] 
Hagen, p. Bost. Soc. XV. pp. 281-288, gives a monographic sketch of 
the species of Pteronarcys. The species called proteus by Pictet is 
considered distinct from Newman's species of that name, and is re- 
named jncteti (p. 286). 
Ephemerid^. 
A. E. Eaton, Tr. E. Soc. 1873, pp. 381-406, has published critical 
notes on his 'Monograph of the Ephemeridce ' (Zool. Rec. viii. p. 405) 
communicated to him by H. A. Hagen in a series of letters, accom- 
panied by remarks of his own. These are principally connected with 
the bibliography and synonomy of the subject, and are too intricate for 
analysis here. 
Oniscigaster, g. n., McLachlan, Ent. M. M. x. p. 109 : differs from 
all known genera by the terminal abdominal segments being dilated 
laterally into broad wing-like lobes. 0. wahefieldi, sp. n., id. I. c. p. 110 
(with figure), New Zealand. 
A swarm of Ephemerids passing through the town of Lewisburg on 
the Susquehanna River, Aug. 22nd, estimated at a mile in length and 
nearly half a mile in width, and so dense as to obscure sight across the 
streets, is noted by Gentry, P. Ac. Philad. 1873, p. 350. 
Odonata. 
Hagen reports on S. H. Scudder's Odonata from the White Mountains 
after an examination of his types : P, Bost. Soc. xv. pp. 376 & 377. 
