168 AMERICAN SPIDERS 



with rounded lobes, protruding trunks, elevated spines, or other 

 curious processes, some of which may bear the eyes. 



Our single species of Rhomphaea is fictilia, a silvery spider with 

 darker bands on the cephalothorax and a single band down the 

 middle of the abdomen. It occurs all over the United States. The 

 body, variable in length and about a quarter-inch long, is somewhat 

 triangular, but in some examples may be drawn out into a vermi- 

 form appendage half an inch long. This long-legged spider spins 

 a tiny web between leaves or blades of grass, where it hangs like a 

 straw. Its egg sac is a yellowish object shaped like a slender vase 

 and about the same size as the spider. Fictilia closely resembles 

 some of the more typical wormlike spiders of the tropical genus 

 Ariamnes, and like them is able to bend its elongated abdomen back 

 and forth. Regarding this appendage, F. O. P. Cambridge has the 

 following to say: 



This, as I have myself observed in Brazil, is wriggled to and 

 fro, looking like a small caterpillar. But of what service to the 

 spider this accomplishment may be is not easy to guess; for on 

 the one hand it seems likely to attract the attention of grub- 

 eating wasps and ants, though on the other it may attract, within 

 striking distance, gnats and small flies who become curious to 

 ascertain what the wriggling phenomenon may portend. 26 



The best-known genus is Conopistha, which comprises the multi- 

 tude of commensal types heretofore known by the generic name 

 Argyrodes, of which quite a number of species occur in the United 

 States. All are known to spin tiny webs of their own, but they are 

 more frequently found hanging in the webs of orb weavers, line 

 weavers, sheet weavers, and not uncommonly in the snares of grass 

 spiders. While hanging in these webs, legs closely drawn together 

 against their bodies, they present an amazing resemblance to straws, 

 twigs, scales, bits of leaves, and debris, so camouflaged that they 

 are completely lost except to the most practiced observer. Largely 

 immune to attack from their hosts because of small size, and per- 

 haps also because of their cautious movement within the lines (in 

 limited sectors of which they lay down threads of their own), they 

 feed upon the tiny insects disregarded by the host. 



One of our commonest species is Conopistha trigona, a yellow- 

 ish, triangular spider scarcely an eighth of an inch long. The ab- 



88 Quoted by J. H. Comstock, in The Spider Book (1940 ed.), p. 352. 



