CHAPTER: 20 
THE TRIANGLE SPIDER: THE ORB SECTOR. 
a. 
Tue snare of Hyptiotes cavatus, the Triangle spider, has awakened 
deep interest among naturalists on account of its peculiar construction and 
manner of operation. The little spinner is equally interesting to the sys- 
tematist, because of its relation to other individuals of its tribe; and in- 
deed because of the question, which has divided arachnologists, as to what 
tribe in the order Aranez it truly belongs. 
I have no hesitation in assigning it to the Orbitelariz, where it seems 
to me that its spinningwork undoubtedly requires it to be placed. On the 
grounds of structure, also, I follow Dr. Thorell and give it the 
same position,! although it must be allowed that the authorities 
are well worthy of consideration who place it among the Clubi- 
onide. As in the case of Uloborus, this is done almost exclusively upon 
the grounds that Hyptiotes possesses the cribellum, a special organ for the 
exudation of spinning material, and the calamistrum, by which such ma- 
terial is manipulated or hackled until it presents the appearance which 
will be further described hereafter. 
The snare is a sector of a circle, including about forty-five degrees of 
the area, and with a radius varying from twelve to twenty inches or less. 
It is thus, as to shape, in strong contrast with the typical orb of 
Epeira, which is a full circle, and with the sectoral orb of Zilla, 
which is a circle lacking its upper sextant, while the net of 
Hyptiotes is just about a sextant or sixth of a circle. In the language of 
Professor Wilder, who has pointed out these relations, to use a more 
homely comparison, the net of Epeira is an entire pie; that of Zilla or 
Nephila is a pie with a piece cut out; while that of Hyptiotes represents 
the missing piece. In algebraic language, Zilla + Hyptiotes = Epeira.? 
(See Fig. 170.) 
The snare is habitually spun in a vertical plane, although it is subject 
to some variation, and I have occasionally found it more or less horizontal. 
It is hung in all sorts of positions between the branches of trees and 
bushes, but its most favorite habitat appears to be pine woods. I have 
System- 
atic Place 
The 
Snare. 
1On European Spiders, page 69. 
2 Professor Bert G. Wilder, Triangle Spider, “Popular Science Monthly,” 1875, page 653. 
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