200 Kew : Snares or Snap-nets of Triangle Spiders. 



description, as we have seen, this author makes special mention 

 of the different points from which the radii diverge ; thus the 

 two snares are doubtless similar in this respect, in which, as in 

 every other respect (except as regards the number of the radii), 

 both exhibit considerable variation. The distances between 

 the radii, says Wilder of the present species, the number of 

 the cross-lines, and the distances between them, as well as the 

 dimensions of the several parts of the snare, all vary consider- 

 ably ; in ten snares, the trap-line (exclusive of the coil of slack) 

 varied from less than half an inch to nearly^ 6 inches; and the 

 triangular net itself from the apex to the base-line, from about 

 4 inches to more than 8 inches ; by McCook the trap-line was 

 found to vary from inches to 13 inches; the net from 



2.y 2 inches to 13 inches ; and one snare measured by this author 

 had a base-line of the extraordinary length of 26 inches. As 

 regards the number of cross-lines, Wilder, as above quoted, 

 gives 6-10, and in his second paper 6-15. Emerton gives 'a 

 dozen or more,' and McCook, while regarding the prevailing 

 number as 16 or thereabouts, notes a range of 5-22. These 

 lines are possibly a little more numerous in the European snare, 

 Thorell, as we have seen, giving 16-22, and Sordelli 15-25. 

 McCook mentions of Hyptiotes cavatus, however, that the 

 number is not constant even with the same individual: thus, for 

 instance, a spider having 14 one day, had 19 on the day follow- 

 ing. In intersecting the radii, these lines do not pass directly 

 across them, but on reaching each radius they run along with it 

 a little way before starting off on the other side ; this condition, 

 well shown in Figs. 4-6, is similar to that obtaining in what 

 is called the notched-zone of certain orb-webs. * The cross-lines 

 are adhesive and highly elastic ; Wilder at first supposed them 

 to be beaded like the spirals of Epeirids ; but he soon found that 

 this was not the case. He states that they are not provided 

 with a fine floss like the characteristic threads of Amaurobiidas, t 

 but are merely double lines, the two strands being from to 

 T0V0 °f an mcn a P ar t- This, however, is not in agreement with 

 the findings of Emerton and McCook, who have shown that 

 these lines are flocculent, somewhat after the fashion of the 

 threads of the family just named, the calamistra doing the 

 curling in both cases. Emerton found a smooth thread running 

 through the centre, the flocculent part of the line being arranged 



* McCook, 1889, torn, cit., p. 187. 

 f Ciniflonidae. 



Naturalist, 



