168 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 
Orbitelarize is vertical, but the corresponding section of the web of the Bas- 
ilica spider, Fig. 18, d d, might be properly described as horizontal, or 
rather as a blending of the horizontal with the vertical. In other 
Linked words, if a horizontal orb attached at the circumference in the 
with Hor- 5 * : 
torum, Usual way were to be lifted up by a thread fastened in the centre, 
it would assume the shape of the dome in the web of the Basil- 
ica spider, In point of fact, this effect might be produced from the charac- 
teristic snares of those species which have been described in the opening of 
this chapter. If, for example, one were to fasten a thread to the central 
point of the orb of Tetragnatha or the Orchard spider, and gradually lift 
it until the orb should assume the dome shape, he would have a snare very 
strongly resembling that of Basilica. The principal difference would be that 
the apron of intersecting lines beneath the dome of the Orchard spider ap- 
pears in Basilica’s web as the underlying curtain; and in addition thereto 
a similar mass of spinningwork appears above the orb. Another difference 
is that the spiral concentrics all have the notched appearance of the few 
central concentrics which compose what I haye named the notched zone. 
Several years after I had observed and published the description of Bas- 
ilica’s web and its relations, substantially as described above, I was greatly 
delighted to have my study confirmed by the observations of Dr. 
Observa- (George Marx, of Washington, D. ©. He had received my ac- 
tions Con- : i et: : ee 
firmed, ©Unt with much skepticism, as indeed did other arachnologists. 
Unfortunately, my description of this entirely new form of orb- 
web, and the remarkable deduction therefrom, were based upon observations 
of a single example both of spinningwork and spider making it. I had no 
doubt of the accuracy of my notes and sketches, which were made with 
care and painstaking, for at the first glance I apprehended the importance 
of the discovery. Nevertheless, I greatly desired to find other examples, 
but searched in vain in the neighborhood of my camp. 
It was, therefore, with unusual satisfaction that I learned from Dr. 
Marx that he had observed several specimens of Basilica in the shrubbery 
on the beautiful parked grounds surrounding the Agricultural Department 
and other public buildings of the national capital. He confirmed my de- 
scription of the character of the web, and added thereto an obser- 
vation of the manner in which the dome is reared. The hypo- 
thetical case, given in my original paper, of the manner in which 
the domed orb of Basilica might be (substantially) erected out of the hori- 
zontal orb of the Orchard spider, proved to be a fortunate anticipation of 
the exact method of the spider. Dr. Marx says that the orb is at first a 
Building 
the Dome. 
1T had gone to Texas with a special purpose, namely, the study of the Agricultural 
Ants; and it was absolutely necessary, in order to follow my line of study and experiments, 
that I should limit the time given to other observations. I have often regretted that I 
could not haye spent a day or two in searching the surrounding district for other examples 
of Basilica, 
—— Po — ead 5 ee 
