PULMONARIiE. 327 



above the others, are longest, and consist of three segments, exclusive of the 

 prominence that forms their peduncle. They weave silken tubes in which 

 they reside, and which they conceal either in holes excavated by them for 

 that purpose, or under stones, bark of trees, or between leaves. 



This genus now forms several divisions, characterized by the number of 

 fusi, the relative difference in the length of the legs and the situations of 

 the palpi. In the 



Mtgale, Walck., 



Or the trtie My gales, the hairs which decorate the under part of their tarsi 

 form a thick and broad brush, projecting beyond the hooks, and usually 

 concealing them. 



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 clefts 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 white web, of a close, very fine texture, semi-diaphanous, and 

 resembling muslin. 



South America and the Antilles produce other species, called by the 

 French colonists Araignees-crahes, or Crab-spiders. Their bite is reputed 

 to be dangerous. A very large species — M. fasciata — is also found in the 

 East Indies. A species, nearly as large as the avicularia, inhabits the Cape 

 of Good Hope. 



In the following Mygales, the superior extremity of the first joint of the 

 chelicerse presents a series of spines, articulated and movable at base, and 

 forming a sort of rake. The tarsi are less pilose underneath than in the 

 preceding division, and their hooks are always exposed. 



These species, in the dry and mountain districts of the south of Europe 

 and of some other countries, excavate subterraneous galleries, which are 

 frequently two feet in depth, and so extremely tortuous, that, according to 

 Dufour, it is frequently impossible to trace them. At the mouth, they con- 

 struct a movable operculum with earth and silk, fixed by a hinge, which, 

 from its form, nicely adjusted to the aperture, its inclination, its weight, 

 and the superior position of the hinge, spontaneously shuts, and completely 

 closes the entrance of their habitation, forming a kind of trap-door, which 

 is scarcely distinguishable from the surrounding earth. Its inner surface 

 is lined with a layer of silk, to which the animal clings, in order to keep its 

 door shut and prevent intruders from opening it. If it be slightly raised, 

 it is a sure indication that the owner is within. Unearthed, by laying open 

 the gallery front of the entrance, it becomes stupified, and allows itself to 

 be captured without resistance. A silken tube, or the nest properly so 

 called, lines the inside of the gallery. There are several species. 



The remaining subgenera are Atypus, Eriodon, Sec, differing in the in- 

 sertion of the palpi, the ligula, number of eyes, &c. 



