198 
Psyche 
[September 
ure 10 shows the results obtained. The values of 10.8 mm and larger 
represent the adult (sexually mature) female spiders. The distribu- 
tion characteristics of the values from 2. 4-7. 7 mm show that only 
one age class of non-reproductive spiders is present; i.e. the pre-re- 
productive period lasts for about two years (from egg to maturity). 
I performed a skewness test on the distribution which verified that 
it represents a sample from a normally-distributed population (P 
O.95 ) . This agrees with the above data obtained from measuring 
web base diameters. Figure 10 does not indicate the length of the 
life cycle following sexual maturity. However, because I found no 
extremely large spiders during the fall, and because of the web base 
measurements (which were not recorded selectively), I feel that 
individuals of H. thorelli reproduce for only one year, with perhaps 
a very small proportion of females reproducing for a second year. 
Although no other papers on hypochilomorph life history have been 
published, one would expect these primitive spiders to have, like H. 
thorelli , life cycles of more than one year. All mygalomorphs have 
life cycles of several years, and a few of the more primitive araneo- 
morphs (some segestriids, scytodids, and filistatids) live for more 
than one year (Gertsch, 1949). Although some higher araneomorphs 
such as an araneid, some lycosids, and a pisaurid (Dondale, 1961) 
require two years to reach sexual maturity, most live for only a 
single year. 
Conclusions 
Although a member of taxa which are phylogenetically and geo- 
graphically relict, Hypochilus thorelli is surprisingly abundant. Its 
success can be attributed in part to the relative abundance of its 
specialized habitat within the southern Appalachians, and to its gen- 
eralized prey-capture mechanism. 
The hypochilomorph spiders are, on morphological evidence, con- 
sidered essentially intermediate between the mygalomorphs and ara- 
neomorphs. This conclusion is also supported by some of the be- 
havorial and life history characteristics of H. thorelli. Its web is 
more advanced than any such structure among the mygalomorphs; 
its method of subduing prey by simply biting it to death is also prim- 
itive. Its life cycle is longer than that of most araneomorphs, yet is 
not as long as that of most mygalomorphs. 
Acknowledgements 
I must express my appreciation for the advice, discussions, and 
