XX. INTRODUCTION. 



and round from the centre in a spiral form ; a large portion of it, 

 towards the outer part of the snare, being thickly studded with 

 very small globules of viscid matter, looking like little drops of 

 dew ; these serve to entangle the flies and other insects when 

 they get into the web. The construction of this kind of snare is 

 carried on, at times, very expeditiously. I have noted a 

 geometric snare completely formed, from beginning to end, 

 within half an hour. 



Geometric webs are placed at different angles with the plane of 

 the earth's surface, according to the species of the constructor, 

 and are not all equally regular, or perfect ; one of the most 

 perfect, among British spiders, is that of Cyclosa {Epeira, Blackw.) 

 conica, Pallas, (pi. iv., fig. 6), while one of the least perfect, 

 among all spiders yet known, is that of Hyptiotes cavata, Hentz. 

 — a North American species. A curious habit of this spider is 

 noted further on. 



The subject of web-spinning is one of the most interesting 

 parts of the study of spiders, though a great deal of leisure and 

 patience are required to carry out any extended observations 

 upon it. It is wonderful to see the great mobility of the 

 abdomen, by which the spinners are directed to any desired 

 point. The legs, and, especially, the claws at the ends of the 

 tarsi, play a very important part here also, enabling the spider to 

 stretch, or to tighten its lines, and to gather them up when slack. 

 Those spiders possessing Calamistra are further enabled to prepare 

 (as before noticed) a peculiarly, flocculent, adhesive web from 

 silk drawn out of the extra spinning organ, with which the 

 Calamistrum is invariably correlated. The geometric snares 

 above described give the name to the great Latreillean group of 

 spiders " Orbitelarice." 



The other great group of snare-spinners is that of the 

 " Retitelarice" Latreille. These must also have been frequently 

 observed by all, excepting the no-eyed part of mankind; 

 their general plan consists of a more or less extended, 

 horizontal sheet of thin web with numerous lines above and 

 below, crossing and recrossing each other in all directions. The 



