PULM0NARI2E. 187 



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 cocoon. 

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

 one-fifth of their length, are used for the divisions of the microme- 

 ter. This observation was communicated to us by M. Arrago. 



Linyphia, 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 re- 

 versed position(l). 



Uloborus, 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 thorax than the two comprised between them, so that 

 this line is arcuated posteriorly. Their jaws, like those of the Epei- 

 rse, begin to widen a little above their base, and terminate in the 

 form of a palette or spatula. 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 seta?. 



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

 is elongated and nearly cylindrical. Placed in the centre of their 

 web, they advance their four anterior legs in a straight line, and 

 extend the two last in an opposite direction; those of the third pair 

 project laterally. 



These Arachnides construct webs similar to those of other Orbi- 

 telse, but they are looser and more horizontal. They will completely 

 envelope the body of a small coleopterous insect in less than three 

 minutes. Their cocoon is narrow, elongated, angular at the margin, 

 and suspended vertically to a web by one of its extremities. The 

 other end is bifurcated or terminated by two prolonged angles 

 one of which is shorter than the other and obtuse; there are two 



(1) Linyphia triangularis, Walck., Hist. desAran., V, ix, female; Aranearesu- 

 pina sylvestris, De Geer; Aranea memtana, L.; Clerck., Aran. Suec, pi. Ill, Tab. 

 I; Aranea resupinu domestica, De Geer. 



