330 ARACHNIDES. 



abdomen is more voluminous, softer, and more coloured than in the pre- 

 ceding tribes. Their webs form an irregular net composed of threads 

 which cross each other in every direction and on several planes. They 

 lie in wait for their prey, display much anxiety for the preservation of their 

 eggs, and never abandon them till they are hatched. They are short-lived. 



There are several genera such as Scytodes, Theridion, Episinus, &c-, dif- 

 fering in the number of eyes, and the mode of their arrangement; the shape 

 of the thorax, &c. 



In the tliird section of the sedentary rectigrade spiders, the Okbitel^, 

 the external fusi are almost conical, slightly salient, convergent, and form 

 a rosette, the legs are slender, as in the preceding section, but the jaws 

 are straight and evidently wider at their extremity. 



The first pair of legs, and then the second, are always the longest. 

 There are eight eyes thus an-anged: four in the middle forming a quadri- 

 lateral, and two on each side. 



The Orbitelse approach the Inequitelae in the size, softness, and diversity 

 of colour of the abdomen, and in their short term of existence; but their 

 web is a regular piece of net-work, composed of concentric circles inter- 

 cepted by straight radii diverging from the centre, where they almost always 

 remain, and in an inverted position, at the circumference. Some conceal 

 themselves in a cell or cavity which they have constructed near the margin 

 of the web, which is sometimes horizontal, and at others perpendicular. 

 Their eggs are agglutinated, very numerous, and inclosed in a voluminous 

 eocoon. 



The threads which support the web, and which can be extended one- 

 fifth of their length, are used for the divisions of the micrometer. 



LiNTPHIA, Lat. 



The. Linyphiae are well characterized by the disposition of their eyes: 

 four in the middle form a trapezium, the posterior side of which is widest, 

 and is occupied by two eyes much larger and more distant; the remaining 

 four are grouped in pairs, one on each side, and in an oblique line. The 

 jaws are only widened at their superior extremity. 



They construct on bushes a loose, thin, horizontal web, attaching to its 

 upper surface, at different points, or irregularly, separate threads. The 

 animal remains at its inferior portion, and in a reversed position. 



UtoBORtrs, Lat. 



The four posterior eyes placed at equal intervals on a straight line, and 

 the two lateral ones of the first line nearer to the anterior edge of the tho- 

 rax than the two comprised between them, so that this line is arcuated pos- 

 teriorly. The tarsi of the three last pairs of legs terminate by one small 

 nail. The first joint of the two posterior ones has a range of small setae. 



The body of these animals, as well as in the following subgenus, is elon- 

 gated and nearly cylindrical. Placed in the centre of their web, they ad- 



