460 



ARACHNIDA. 



The second section of the sedentary and rectigrade Spiders — that of the Lveciuitel.e or Spinning 

 Spiders {Araiynees filandieres), has the external spinnerets nearly conical, very slightly exserted, 

 convergent, arranged in a rosette, and the legs very slender. The maxilhe incline towards the tongue, 

 and are narrow at the tip, or at least are not dilated. The majority have the first pair of legs, and 

 then the fourth, the longest ; the abdomen is larger, softer, and more coloured than in the preceding 

 tribes. They construct webs with irrregular meshes composed of threads, which cross in all directions 

 and different surfaces. They whirl threads round their prey, take great pains in the preservation of 

 their eggs, and do not leave them until they are hatched. They live but a short time. 



Scyiodes, Latr., has only six eyes, arranged in pairs, and the ungues of the tarsi are inserted upon a supple- 

 mental joint. <S. thoracica, Latr., inhabits the interior of our apartments ; another species, <S. rubcscens, was 

 found by Dufour in the mountains of Valencia. It fabricates an irregular tube of slender texture, of a milky- 

 white, like that of Dysdera erythrina. 



Theridion, Walck., has eight eyes thus arranged, four in the middle in a square, the two anterior ones placed on 

 a protuberance, and two on each side, also placed on an elevation common to both ; the thorax is like a reversed 

 heart, or nearly triangular. The species are very numerous. Type, Aranea 13-guttata, Fabr., Rossi. — Found 

 in Tuscany and the island of Corsica. Its bite is considered very venomous, and even mortal.* — (See the Tableau 

 and the IJistoire des Araneides of Walckenaer; the Annates des Sci. Naiur., and the Ann. des Set. Physiq.) 



A. mactans, Fab., an American species, is similarly dreaded. These fears seem more to originate in the black 

 colour of the animals, which are marked with blood-coloured spots. T. benignum, Walck., takes up its abode in 

 bunches of grapes, and thus defends them from the attacks of other insects. 



Epirinus, Walck., — has also eight eyes, but which are placed close together upon a common elevation of the 

 narrow and subcylindric thorax. E. truncatus, Latr. Paris, Italy. 



Pholcus, Walck.,— has the first and then the second legs the longest; the eyes, eight in number, are placed upon 

 a tubercle, and arranged in three groups, one on each side composed of three eyes placed in a triangle, and the two 

 others in the middle, in a transverse row. Ph. Phalangioides, Walck., has the body long and very narrow, of a 

 very pale livid colour ; abdomen very soft, and marked above with blackish spots; legs extremely long and very 

 slender, with a white ring at the tip of the thighs and tibiae. It is common in houses, where it spins a web 

 composed of loose threads in the angles of walls. The female gums her eggs into a rounded naked body, which it 

 bears about in its jaws. Dufour found another species in the crevices of rocks in Valencia. Like the preceding, 

 it balances itself backwards and forwards upon its very slender feet. 



The third section of the sedentary rectigrade Spiders is that of the Orbitel^e, or the Araiynees 

 tendeuses of some authors, having the external spinnerets nearly conical, slightly exserted, convergent 

 and arranged in a rosette, the legs slender, and the maxillae straight or sensibly widened at the tip ; 

 the first pair cf legs, and then the second, are always the longest. The eyes are eight in number, and 

 thus arranged, — four in the middle in a square and the two others on each side. They resemble the Ine- 

 quitelae in the size, softness, varied colours of the abdomen, and shortness of their lives ; but they make 

 their webs with regular meshes, arranged in concentric circles crossed by straight radii extending from 

 the circumference and meeting in the centre, where the insects remain stationary and in a reversed 

 position. Some species secrete themselves in a cavity or cell which they construct near the edges of 

 the net, which is sometimes horizontal and sometimes perpendicular. The eggs are agglutinated 

 together, very numerous, and inclosed in a large cocoon. The threads which support the web, and 

 which stretch to ahout a fifth their length, are used for the divisions of the micrometer, an astronomical 

 instrument, as we learn from M. Arago. 



Linyphia, Latr., has four of the eyes in the middle, forming a trapezium widest behind; the two hinder eyes 

 being larger than the rest, and the four others, arranged in two pairs, one on each side and in an oblique direction. 

 The maxilla; are dilated at the tip. L. triangularis, AValck. ; Aranea montana, Linn., &c. They construct upon 

 various shrubs an horizontal slender web, attached by irregular threads in many points ; this web is thus a 

 melange of those of the Inequitela and Orbitelce. The insect stations itself on the under side in a transverse 

 position. 



Uloborus, Latr., has the four posterior eyes placed at equal distances in a straight line, and the two lateral ones 

 of the front line nearer the front edge of the thorax than the two intermediate ones. The maxilhe w iden from 

 near the base, and are spatulated at the tip; the tarsi of the three hind pairs of legs are terminated by a single 

 unguis. The body is long and subcylindrical. When stationed in the middle of their web, they stretch their four 

 fore-legs forward in a straight line, and their two hind ones in an opposite direction, the third pair being laterally 

 extended. They make webs like the other Orbitelse, but looser and horizontally. The cocoon is narrow, long, 

 angular at the sides, and suspended vertically by one end to a net; the other end is produced into two points, as 

 stated to me by M. Dufour. U. Walchenaerius, Lat. ; found in the woods of the environs of Bordeaux, and other 

 southern departments ; five lines long. 



* This species is the type of Walckeuaer's genus Latrodectes, founded upon supposed differences in the relative length of the leg s. 



