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PREFACE. 
When exceedingly minute spiders are made the subjects of investigation, it is essential that 
the sexual organs should be closely inspected, as they afford, by their complete development, an 
infallible criterion that the animals have arrived at maturity; they also present, by their greatly 
diversified organization, particularly as regards the males, in which sex they are connected with 
the digital or terminal joint of the palpi, excellent specific characters, the value of which will be 
duly appreciated when it is l’ecollected that many species so neai’ly resemble each other in size 
and colour as to be distinguished by differences in structure only. 
The difference in the number of eyes with which spiders are provided, supplying, as it does, 
well-marked characters not difficult to be ascertained, has been taken as the most convenient and 
satisfactory basis of their distribution into tribes. On this principle the three following tribes 
have been founded, which include all the species hitherto discovered: 
1. Octonoculina; eyes eight. 
2. Senoculina; eyes six. 
3. Binoculina ; eyes two. 
The first tribe, Octonoculina, is much the most extensive of the three, comprising numerous 
genera, which exhibit considerable differences in organization and economy; the second tribe, 
Senoculina, includes ten or eleven genera, species belongiixg to many of which are found in this 
kingdom; and the third tribe, Binoculina, contains the single genus Nops, instituted by Mr. W. 
S. MacLeay for the reception of two remarkable species of extra-European spiders. It may be 
further remarked, that to the families previously established another has been added, namely, 
the Cinijlonidce; and that several new genera have been introduced, whose characters are defined 
in their appropriate places. 
In preparing the following pages for publication, the principal authorities consulted were 
Lister, Latreille, Walckenaer, Sundevall, Hahn, Koch, Wider, Duges, Audouin, Owen, &c., 
from whose writings much valuable information has been derived. 
♦ 
It remains to acknowledge the kind assistance of friends from whom specimens have been 
received; but as the obligations to each will be expressed as suitable occasions present 
themselves, it is not requisite to allude to them more particularly in this place. 
