18CS.J 11 
under the bark of a dead oak ti-ee, and seems to be vexy rare, for, 
though we carefully examined the greater part of the same tree, we 
were unable to find a second specimen. 
In my present notice I shall only give a summary of the characters 
of these species, as the time must soon arrive when they will be de- 
scribed at greater length. To them I will also add the diagnostic 
characters of a genus, which I have separated from Ptilium, to contain 
the following species, viz., Pt. transversale, Erichson, Pf. concolor. 
Sharp, and P^. coarctatum, HaHday ; these all differ widely from Ptilium 
in every anatomical detail ; the most obvious distinction exists in the 
base of the thorax, which is not, as in the true Ptilia, fitted to the 
shoulders of the elytra, but overlaps and lies upon them, so as partly 
to conceal the scutellum. It is not unlikely that the name of the last 
of these three. Act. coarctatum, will have to be altered ; in 1855 Mr. 
Haliday described this species, in the Dublin Natural History Eeview, 
p. 124, under the name of Ptilium coarctatum, and in the same year, 
M. Thomson described it, in the Ofvers. af Vet. Acad. Forhl., p. 339, 
under the name of Ptilium elongatum ; the priority must therefore be 
determined by the month of publication, and this I have not yet been 
able to ascertain : that the names are merely synonyms of a single spe- 
cies there can be no doubt, for M. Thomson has very kindly sent me 
his unique example of elongatum for comparison, and it is specifically 
identical with Mr. Haliday's type of coarctatum. 
This species is another remarkable instance of eccentric distribu- 
tion ; it was discovered almost simultaneously by Mr. Haliday in 
Ireland, and M. Thomson in Sweden, and has subsequently been taken 
by M. Aube on the shore of the south of France, and by Col. Mots- 
chulsky in Egypt. As I have made this species the type of the new 
genus, I have termed the latter Actidium, in reference to its habits ; its 
allies, though not strictly littoral, are found among sand and gravel on 
the margins of rivers and lakes. 
Teichopteetx axtheacina, Matthews, Ent. Mo.Mag.,ii, 35, 1865. 
L. c. -^ lin. Ovata, maribus postice valde attenuata, valde con- 
vexa, nigra, nitida, pilis brevibus argenteis parce vestita, capite modieo, 
antice elongato, oculis sat magnis, prominulis ; pronoto modieo, valde 
convexo, postice dilatato, tuberculis sat magnis, ordinibus irregulariter 
siuuatis confertiin dispositis, interstitiis nitidis, subtiliter retioulatis, 
