1891.] Entomology. 1051 
Spermocoecus Giard. ; France. 
Exerectopus Newst.; Channel Is. 
Ericerus Guér. ; China. 
Fairmairia Sign. ; France. - 
Ischnaspis Doug]. ; West Indies, etc. 
Frenchia Mask.; Australia. 
Of the above twenty-six monotypic genera, most of which are un- 
doubtedly valid (seven, perhaps, might be questioned), it will be seen 
that just half are European, four are Oriental, four appear to belong 
to the Australian region, two are Mexican, two are marked as from 
the West Indies, etc., and one is from the arid portion of the United 
States. . 
Signoretia offers a singular case, the European species being repre- 
sented in Australia by a form which Maskell separates from it only as 
a variety. Supposed endemic species of Signoretia from Australia 
and New Mexico prove to belong to Pulvinaria and Bergrothia re- 
spectively ; and it is difficult to avoid the conclusion that S. luzulæ 
var. australis Maskell, from Australia, must be S. luzulæ which has 
been introduced and has varied from the type under its new environ- 
ment. If so, the matter deserves the close attention of evolutionists. 
It is curious that the common Physokermes of Europe has no repre- 
sentative here in America. We have two species of Lecanium on con- 
ifers, one in Canada, the other in California, but they are not like 
Physokermes. 
So, also, we seem to have no representative of the subterranean 
European genera, Aclerda, Spermococeus and Exeretopus. Do our 
ants’ nests never harbor such ? 
Fairmairia has a close ally in northern Mexico and New Mexico in 
Ceroplastodes—the latter with two species. A curiously similar case 
is offered by Lichtensia, which has one species in Europe and another 
in Vera Cruz, Mexico. The latter, one of the most beautiful of Cocci- 
dæ, from its brilliant yellow color, cannot be made the type of a distinct 
genus, though it is very different from its European congener. 
"insonia and Ischnaspis (the latter near to Fiorinia) are common 
on eultivated plants in the West Indies, but the specimens offer no 
chance for the separation of even varieties. — Jschnaspis, it will be 
noted, is the only monotypic genus of Diaspine. 
The Monophlebinz appear to be ancient forms, probably at one time 
more abundant than now. They have been found fossil both in 
Europe and America; and the existing genera are represented by 
comparatively few species widely scattered over the earth, after the 
