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Show 180 ARACllNIDE!. their legs are elevated when at rest; sometimes the two firs.t and two last are the longest, and at others those of the two anter10r pairs, or the fourth and the thit·d. The general arrangement of the eyes does not for·m the segment of a circle or a Ct'escent. They may be divided into three secti.ons: th? first, or t~at of the Tubitdre, has cylindrical fusi approximated mto a fasciculus di· rected backwards; the legs are robust, the two first or the two last, and vice vet·sa, longest in some, and the whole eight nearly equal in others. We will commence with two subgenera, which, with respect to the jaws that describe a circle round the ligula, approach the Filistatre, and at'e removed from those that follow. CLoTHo, Walck.-Uroctea, Dufour. A singular subgenus. The chelicer~ are very small, can sepa· rate but little-thereby approximating this subgenus to the lastand are not indented; very !;mall hooks; the shortness of the body and length of the legs produce a resemblance to the Crab-Spiders or Thomisi. The relative length of these organs differs but little; the fourth pair, and then the preceding one are merely somewhat longer than the first; the tarsi, only, are furnished with spines. The eyes are further from the anterior margin of the thorax than in the fol· lowing subgenus, and arc approximated and arranged as in the genus Mygale of Walckenaer; three on each side fot·m a reversed triangle; the two others form a transverse line in the space comprised between the two triangles. The jaws and the ligula are proportiona· bly smaller than those of the same subgenus; a short projection or slight dilatation on the external side of the jaws, gives insertion to the pal pi; the jaws terminate in a point; the ligula is triangular and not nearly oval as in Drassus. The two superior or most lateral fusi are long, but what, according to Dufour, particularly charac· terizes his Uroctere or our Clothos, is, that there are two pecti· niform valves which open and shut at the will of the animal(!), in place of the two intermediate fusi. But a single species is known, the Uroctea 5-maculata, Du· four, Ann. des Sc. Phys., V, lxxvi, 1; Clotho Durandii, Lat. ( 1) I have seen, in a well preserved specimen, six fusi, of which the two superior were much the longest and terminated by an elongated joint, forming an elliptical lamina, and the other four small, the inferior ones particularly, and ar· ranged in a square. Th.e anus, placed under a little membranou11 projection resembling a clypeus, was fm·nished on each side with a pencil of retractile hairs. These pencils at·e the parts named by Dufour pectiniform valves, a.nd are distinct from the two intermediate fusi, which are concealed by the two inferior ones. PULMON AIUJJ!.. 181 The body is five lines in length, of a fine chesnut colour; abdomen black; five small, rountl, yellowish spots above, four of which are arranged tt'ansversely in pairs, and the last or fifth posterior; legs hairy. It is evident from the plates of the great work on Egypt, that M. Savigny found it in that country, and proposed forming a new genus with it. Count Dejean brought it from Dalmatia; and Schreiber, director of the Imperial Museum of Vienna, has sent me specimens captured in the same countt·y. M. Dufour also found it in the mountains of N arbonne, in the Pyrennees and among the rocks of Catalonia. To this latter· natut'alist we are indebted not only for our knowledge of the extern~l characters of this spider, but for many curious observations relative to its habits. '' She constructs," says he, "a shell resembling a calotte or patella an inch in diameter, on the under surface of large stones or in the fissures of rocks. Its contour presents seven or eight emarginations, the angles of which are alone attached to the stone by silken fasciculi, the margin being free. This singular tent is admirably woven. The extet'ior resembles the very finest taffeta, formed, according to the age of the animal, of a greater or less number of layers. Thus, when the young Uroctea first commences het• establishment, she merely forms two webs between which she seeks for shelter. Subsequently, and I believe at each change of tegument, she adds a certain number of layers. Finally, when the nuptial season has arrived, she lines an apartment with a softer and more downy material which is to enclose the sac of eggs and young ones. Although the exterior shell is more or less soiled by foreign bodies which serve to conceal it, the chamber of the industrious architect is always extremely neat and clean. There at'e four, five, or six eggpouches or sacculi in each domicil; they are lenticular, more than four lines in diameter, and formed of a snow-white taiTeta lined with the softest down. The ova are not produced till the latter eutl of December or the beginning of January; the young are to be protected from the rigour of winter and the incursions of e.ne~ies-all is prepared; the receptacle of this precious deposit IS separated ft·om the web that adheres to the stone by soft down, and from the external calotte by the various layers I hav~ .mentioned.. Some of the emarginations in the edge of the pavlhon are completely closed by the continuity of the web, the edges of the remainder are merely laid on each other, so that by raising them up, the animal can issue from its tent or enter it, at pleasure. When the Uroctea leaves her habitation for the chase, she has nothing to fear, she only posses&es the' |