Short Papers and Notes. I47 
correspondent of the /ve/d, is well known to naturalists as the 
formidable antagonist of the young fry in our fish-ponds, and the 
writer has frequently witnessed scenes of ruthless slaughter 
on the introduction of one of these beetles into a fresh-water 
aquarium. Although scarcely two inches in length, it has a 
formidable appearance with its powerful mandibles and active 
form. If two dytisci are placed in a small glass bowl, one will 
very soon transfix the other and decapitate him. The following 
account of a duel, in which a large garden spider and a dytiscus 
were the principals, may be of interest:—The spider was placed on 
an islet of rock-work, in a small aquarium, while dytiscus lurked 
in a weedy bower beneath the surface; the spider seemed ill at 
ease, and evidently thought his quarters lacking in those con- 
veniences which are essential to the well-being of web-spinners. It 
was not long before the dytiscus rose to the surface, and, seeing the 
stranger by the water’s edge, promptly closed with him, seizing the 
huge body of the spider with his sharp pinchers. The two rolled 
over in the water, but after a sharp tussel they separated, neither 
apparently any the worse for the scrimmage. The spider was 
placed once more on the islet, and by gently disturbing the water 
with a twig dytiscus was again brought to the scratch, this time 
with fatal result. The spider at one time had fastened himself on 
the dytiscus; but the latter, using his pinchers to more purpose 
than in the first encounter, killed the spider, and the fight was 
over. Dytiscus, however, was evidently badly hurt, and after some 
convulsive movements also succumbed. 
The Great Wellowstone Geyser, 
The Excelsior Geyser in Yellowstone Park, U.S.A., is at present 
(July, 1888) in eruption. This geyser is in the great middle geyser 
basin, close to Fire-Hole River. It is in the form of an immense 
pit, 320 feet in length and 200 feet in width, and the aperture 
through which it discharges its volume of water is nearly 200 feet 
in diameter. Its general appearance is that of a huge boiling 
spring, and for many years its true character was not suspected. 
Its first eruption occurred in 1880, when it revealed itself as a 
stupendous geyser. The power of its eruptions was almost 
incredible, sending an immense column of water to heights of 
from too to 300 feet, and hurling with it rocks and boulders of 
from one pound to one hundred pounds in weight. The present 
eruption is said to be a repetition of that of 1880. It is throwing 
its volumes of water 300 feet into the air, and Fire-Hole River is 
reported to have risen two feet from its rushing floods. This is 
now conceded to be the most powerful geyser in existence. 
