18 
similar way the crystals which it would 
throw down. But this must be left to the 
petrologists. I cannot, however, express 
too strongly my appreciation of the value 
of Lord Kelvin’s stalwart opinion respect- 
ing the incompetency of the thermal theory 
of crustal deformation, since this carries 
with itself, more remotely and occultly 
(pace Kelvin) an implication of like weak- 
ness in the theory of the white-hot earth 
itself. 
T. C. CHAMBERLIN. 
UNIVERSITY OF CHICAGO. 
A DANGEROUS EUROPEAN SCALE INSECT 
NOT HITHERTO REPORTED, BUT AL- 
READY WELL ESTABLISHED IN 
THIS COUNTRY.* 
In view of the activity and zealousness 
displayed by several of the European states 
in excluding American plants and fruits on 
the pretext of possible contamination with 
the San José scale, it is opportune perhaps 
to call attention to the fact that a dangerous 
and perhaps very dangerous European scale 
insect, Aspidiotus ostreeformis Curtis, has re- 
cently become well established in this coun- 
try. This scale insectis very similar to the 
San José scale in general appearance and 
habit, and is liable to be almost, if not 
equally, as mischievous, judging from the 
examples of badly infested material which 
have come to this office for determination. 
Aspidiotus ostreeformis is a well-known 
pest on various fruit trees in Europe, where 
it hasa very wide distribution,but, strangely 
enough, in view of the ease of its importa- 
tion on nursery stock, seems not to have 
gained lodgment in this country until com- 
paratively recently. The first examples of 
*The scale insect on pear and apple at Alameda, 
Cal., collected by Mr. Koebele and determined by 
Professor Cockerell as ostrexformis (Bul. 6, Tech- 
Ser., Div. Ent., U. 8S. Dept. Agric., p. 19.), is a case 
of wrong identification ; the species is juglans-regix, 
as I have determined from examination of the original 
material. 
SCIENCE. 
[N.S. Von. X. No. 236. 
ostreeformis coming to this office from 
American sources were naturally confused 
with other species, being identified either as 
ancylus, juglans-regie or forbesi, all near 
allies ; and while ostreeformis has undoubt- 
edly been established in New York and 
Ohio for eight or ten years, and in other 
localities for shorter periods perhaps, its 
existence in this country has not hitherto 
been reported in print, and specific identi- 
fication has only been established within 
the last year. In fact, so little is the spe- 
cies known that two experts in Coccidee 
were prepared recently to describe as new 
an example, referred to below, coming to 
Dr. James Fletcher from Pocum, British 
Columbia. The fact that this material 
represented the European ostreceformis, now 
first shown to occur in this country, was 
fortunately determined by Mr. Theo. Per- 
grande in time, I believe, to prevent the 
publication of the new species. 
Within the last few months material 
representing ostreeformis has come to this 
office and been determined by the writer 
very frequently, especially from the State 
of New York, where it seems to have be- 
come well established, notably in the 
vicinity of Geneva. No less that 15 lots of 
this scale insect have been determined from 
Geneva, N. Y., representing as food plants 
plum, cherry and apple. Most of this 
material has been communicated by Mr. G. 
G. Atwood, either direct or through Mr. 
Felt. In one case the food plant is des- 
ignated as ‘ European plum,’ and the state- 
ment is made by Mr. Atwood that the scale 
occurs in numbers on this food plant, to its 
considerable injury. Additional localities 
in New York are: Rochester, on apple (H. 
C. Peck and V. H. Lowe) ; same locality, 
on plum (Dr. Peter Collier), and Mill- 
brook, on pear (E. ©. Butterfield, reported 
as badly infesting 7 pear and 12 plum trees 
imported eight years before from a German 
firm); Penfield, on apple (Felt) ; and also 
