A history of the spiders of Great Britain and Ireland

Preface

Our celebrated countryman, Dr. Martin Lister, in bis admirable ‘ Tractatus de Araneis,’ bas given a classification of the species be lias so ably described, founded on their external organization and economy, which has formed the basis of every subsequent attempt, deserving of notice, to effect a systematic arrangement of this interesting order of animals.

Since the publication of Dr. Lister’s treatise in 1078, little attention has been bestowed upon the natural history of spiders in this country, till within the last thirty years; and we are indebted for almost every advance which has been made in it during that long interval of time to the talent and industry of the continental zoologists, particularly those of France, Sweden, and Germany.

Under these circumstances, it is hoped that the present imperfect endeavour to supply that desideratum in the zoology of Great Britain, a history of our indigenous spiders, adapted to the existing state of arachnological science, will be regarded with due consideration for the numerous and great difficulties by which the undertaking is surrounded.

Although a large addition has recently been made to the knowledge of our native species of Araneidea, yet the subject is far from being exhausted; a wide field still remains to be explored by succeeding arachnologists ; and if the present work should tend to promote and facilitate the researches of others in this department of zoology, one of the most important purposes which it is intended to subserve will be accomplished.

In taking the dimensions of spiders, it is desirable that the relative length of their legs should be ascertained with exactness; and this object may be conveniently attained by submerging the specimens to be examined in spirit of wine till life is extinct; then, on removing them to a piece of white cardboard and carefully extending the limbs with a pin, while they are pliable, their extent, from the margin of the cephalo-thorax to their extremity, may be taken with a pair of compasses, which on being applied to a scale of inches and parts will give their measurement. The length of species is determined by measuring them from the anterior part of the cephalo-thorax to the extremity of the abdomen, not including the falces and spinners.

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 recollected that many species so nearly 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 tiibe, 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 belonging to many of which are found in this kingdom; and the third tribe, Binoculina , contains the single genus JYops, 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 CinijionidcB; 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 waitings much valuable information has been derived.

It remains to acknovdedge 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.