174 ARACHNIDES. 



reversed triangle, and the two superior ones approximated; the 

 remaining two arranged transversely between the preceding. 



The fourth pair of legs arc the longest, and then the first; the 

 third is the shortest. 



Here the palpi are inserted into the superior extremity of the 

 jaws; so that they appear to consist of six joints, the first of which, 

 narrow and elongated, with the internal angle of the superior extre- 

 mity salient, fulfils the functions of a jaw. The ligula is always 

 small and nearly square. The last joint of the palpi of the males 

 is short, has the form of a button, and bears the organs of genera- 

 tion at its extremity. The two anlerior legs of the same sex have a 

 stout spine or spur at their inferior extremity. Such are the cha- 

 racters of the 



Mygale, Walck. , 



Or the true Mygales. In some of them we find no transverse 

 series of horny and movable spines or points, resembling the teeth 

 of a rake, at the superior extremity of their chelicerse immediately 

 above the insertion of the claw or hook which terminates them. 

 The hairs which decorate the under part of their tarsi, form a thick 

 and broad brush, projecting beyond the hooks, and usually conceal- 

 ing them. The male organs of generation consist of a single scaly 

 piece, terminated by an entire point, or neither emarginated nor 

 divided; sometimes it is formed like an ear-pick — M. de la Blond, 

 Lat. — usually, however, it is globular inferiorly, then becomes nar- 

 row, terminates in a point, and forms a kind of arcuated hook. 



This division is composed of the largest species of the family, 

 some of which, when at rest, cover a circular space of from six to 

 seven inches in diameter; they sometimes seize upon Humming- 

 birds. They establish their domicil in the clefis of trees, under the 

 bark, in the fissures of rocks, or on the surface of leaves of various 

 plants. The cell of the Mygale avicularia has the form of a tube, 

 narrowed into a point at its posterior extremity. It consists of a 

 Avhite web, of a close, very fine texture, semi-diaphanous, and resem- 

 bling muslin. One of them, presented to me by M. Goudot, when 

 unrolled, was about two decimetres in length, and six centimetres in 

 breadth, measured across its greatest transversal diameter. The 

 cocoon of the same species was of the figure and size of a large 

 walnut. Its envelope, consisting of the same material as that of its 

 domicil, was formed of three layers. It appears that the young arc 

 hatched in it, and undergo their first change of tegument there. 



