ADVERTISEMENT. 



THE original price of this work was placed at thirty dollars ($30) per set of three 

 volumes. In the announcement thereof in a prospectus of August 1st, 1889, special terms 

 were offered to subscribers who should send their names before the 1st of November of the 

 same year. A number accepted this offer, and are, therefore, receiving the entire series for 

 twenty-five dollars. With the issue of the first volume this special offer ceased, and the 

 price thereafter remained as fixed, namely, ten dollars per volume, until January 1st, 1892. 

 At that date, by public notice, the price of the work was fixed at ($50) fifty dollars. 

 This is the present selling price, and will thus remain, at least as long as the author retains 

 control of the issue. No separate volume will be sold. 



The author was induced to assume the disagreeable role of publisher by two considera- 

 tions, first, the wish to be free to present the book according to his own ideas as to 

 typography and illustration, which, however, were too luxurious to meet the views of 

 ordinary publishers. In the second place, as a commercial venture, the printing of a 

 scientific work of this sort, with so limited a circulation, gave no prospect of remuneration 

 for cost and care. It is indeed a work of love, and must be carried forward chiefly from a 

 desire to enlarge the bounds of truth. Moreover, the cost was too considerable to warrant 

 any Scientific Society to undertake the work of publishing from funds always too limited. 

 The author therefore accepted the burden of cost, together with the yet more uncongenial 

 details of selling, as a part of his task. He has planned and now aims to obtain from the 

 sale as nearly as possible the actual expenditure in money for printing and engraving. 

 With this in view he was compelled to correct the mistake made at the outset of placing 

 the work at so low a price. 



The several volumes will be mailed to subscribers with uncut edges, for the accommoda- 

 tion of those who wish to give them special library binding. 



The Author's Edition is strictly limited to two hundred and fifty copies, which will be 

 numbered consecutively in the order of subscription as received. 



The first two volumes are devoted to a description of the industry and habits of Orb- 

 weaving spiders, both separately and in their relations to the spinning economy of other 

 aranead tribes. The first volume treats particularly of Snares and Nests ; the second volume 

 considers the Cocooning Industry, Maternal Instincts, and General Habits. These volumes 

 are liberally illustrated by drawings from nature, containing in all 853 figures, drawn 

 and engraved for the work, many of these cut upon the wood, and a large number of full 

 page illustrations. Besides these there are forty lithographic plates, colored by 

 hand from nature, upon which are engraved 913 figures. In addition, a full page portrait* 

 of Professor Hentz, the father of American Araneology, has been made the frontispiece of 

 Volume III. The third volume contains six chapters of Natural History descriptions, illus- 

 trated by ninety-eight engravings. The remainder and principal part of the volume is 

 devoted to descriptions of the Orbweaving fauna of the United States, and two plates 

 illustrating typical species of the other aranead groups. 



Subscriptions may be made directly without the intervention of a bookseller, but a 

 slight discount will be allowed to the trade. 



All business communications and subscriptions may be addressed directly to the author or to 



" AMERICAN SPIDEKS AND THEIR SPINNINGWORK," 



ACADEMY OF NATURAL SCIENCES, 



LOGAN SQUARE, PHILADELPHIA, U. S. A. 



