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Show 174 ARACltNIDES. reversed triangle, and the two superior ones approximatrcl; the remaining two arranged transversely between the preceding. The fourth pair of legs are the longest, and then the first; the third is the shortest. Here the palpi are inserted iz~to the. s~~erior extremity of the jaws; 80 that they appear to constst of SlX JOints, the first of whic~ 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 orga,ns of grnera· tion at its extremity. The two anterior 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 theit· chelicerce immediately above the insertion of the claw or hook which terminates them. The hairs which decorate the under part of theit· 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 becomesnar· row, terminates in a point, and forms a kind of arcuatcd 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 clefts of trees, under the bark, in the fissures of rocks, or on the surface of leaves of val'ious 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 ~cb, of a close, very fine texture, semi-diaphanous, and t·esem· bling muslin. One of them, presented to me by M. Goudot, when unrolled, was about two deoimetres 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 are hatched in it, and undergo theit· first change of tegument there. PULMONARilE. 175 The naturali.st just mentioned, stated to me, that he had taken a dred of them from a single cocoon( I). bun This Mygale--.Oranea avicularia, L.; Kleem. Insect. XI, and XII, the male-is about an inch and a half long, blackish, and extremely hairy; the extremity of the feet and palpi, and the inferior pili of the mouth reddish. The genital organ of the male is hollow at base, and terminates in an elongated and very acute point. South America and the Antilles produce other species, called by the French colonists .Oraignees-crabes. Their bite is reputed to be dangerous. A very large specie s-M. fasciata; Seb., Mus., I, lxix, i; Walck., llist. of Spiders, IV, i, the female -is also found in the East Indies. A species, nearly as large as the avicularia, inhabits the Cape of Good Hope. Another of the same division-M. Valentina-was discovered in the sandy and desert districts of Moxenta, in Spain, by M. Dufour, who has described and figured it in the Ann. of the Phys. Sciences, Brussels, vol. V. Walckenaet' has also described a second species ft·om that peninsula which has two prominences above its respiratory organs. These two latter species form a particular group, characterized by the hooks of the tarsi, which are salient or ex posed( 2 ). In the following Mygales(3), the superior extremity of the first joint of the chelicerce presents a series of spines, articulated and movable at base-according to the observations of Dufour-and forming a sort of rake. The tarsi are less pilose underneath than in the preceding division, and their hooks areal ways exposed. The males of one species, the only ones I have seen, have more complicated organs of generation than those of the preceding division. The principal and scaly piece incloses a peculiar, semiglobular body, tet·minating in a bifid point, in an inferior cavity( 4). These species, in the dry and mountain districts of the south of Europe and of some other countries, excavate subterraneous galle- (1) See my memoir on the habits of the Avicularia in the Ann. du Mus. d'Ilist. Nat. VIII, p. 456. (2) For details concerning these and the following species, as well as for the other genera of this family, see the corresponding articles in the Nouv. Diet. d'Hist. Nat., where wt: treat of them at length. (3) The genus C-rENIZA, Lat., I~am. Nat. du Regne Animal. (4) On this point I am contt·a.dicted by M. Dufour. 1 was compelled again to examine the fact, and have convinced myself that 1 was not mistaken. It is possible the specimens he examined did not present this character. |