356 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 
lineweaving adjunct to its web. We have seen it in the case of Argiope, 
though not so strongly developed and not universally possessed by the in- 
dividuals of that genus. We have seen it more decidedly and 
Epeira permanently fixed upon Epeira triaranea and Epeira thaddeus. 
and The- But, to a greater or less extent, it may be said that the lineweay- 
saci ut, greate ' y at the lineweay 
ing habit belongs to the Orbweavers, though by way of associa- 
tion with and subordination to their typical orbicular snare. 
It may further be worth noting, in this connection, that not all the 
Epeiroids make use of a round snare. There is a wide difference between 
the mere sector of an orb made by Hyptiotes and the web made 
by Epeira triaranea or Epeira labyrinthea, and which I have 
denominated a sectoral orb. Yet the last named snares are only 
larger sectors of circles, like that of Nephila, for example. By turning to 
the description of the manner in which the interradials of Nephila are 
woven in, it will be seen that it substantially resembles that used by Hyp- 
tiotes and, indeed, by Dictyna, when placing in its spirals of flocculent 
thread. In other words, the sectoral orb is made by a series of loops 
passing over the sector of a circle larger or smaller, as the case may be. 
Moreover, a very considerable group of the Orbweavers spin horizontal 
orbs; and it is interesting to observe that Uloborus, which is related to 
, Orbweavers generally by its round web, and to the Tubeweavers 
ors through Hyptiotes and Dictyna by their nonviscid armature of 
flocculent spirals, spins a horizontal web like that group of the 
Epeirinee to which the Orchard and the Hunchback spiders belong. 
Thus it has been shown that one may pass by natural gradations, 
through forms more or less distinctly marked, from the simpler and seem- 
ingly more primitive spinningwork, to the various orbicular snares, 
ae which may be considered the most complex of all known webs. 
These relationships are often very striking, and, on the whole, 
beautifully indicate the industrial unity of the entire order Aranez. 
Nevertheless, no one better knows than the student of spider habits how 
vast are the intervals which, at many points, have no more substantial 
bridge than that which imagination or analogy may supply. When arach- 
nologists shall have more thoroughly wrought out the natural history of 
spiders, some of these interspaces may be united or more nearly 
Unity of approached, Perhaps some species have disappeared whose spin- 
Industrial _. He ; aot ane ; : 
Habit. ningwork might have furnished missing industrial links. Never- 
theless, the veritable facts of science can go no further than to 
show the points and degree of approach, and exhibit the general har- 
mony, one might almost venture to say the germinal unity, of industrial 
habit which marks the children of Arachne. 
Sectoral 
Orbs. 
THE END. 
