PULMONARI^E. 293 



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 cliamber of the industrious 

 architect is always extremely neat and clean. There are four, 

 five, or six egg pouches or sacculi in each domicil ; they are len- 

 ticular, more than four lines in diameter, and formed of a snow- 

 white taffeta lined with the softest down. The ova are not pro- 

 duced till the latter end of December or the beginning of 

 January; the young are to be pi'otected from the rigour of 

 winter and the incursions of enemies — all is prepared ; the recep- 

 tacle of this precious deposit is separated from the web that 

 adheres to the stone by soft down, and from the external calotte 

 by the various layers I have mentioned. Some of the emar- 

 ginations in the edge of the pavilion arc 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 possesses the secret of the impenetrable emargination, and 

 has the key to those which alone afford an entrance. When her 

 offspring are able to provide for themselves, they leave their 

 native dwelling, to establish elsewhere their individual habita- 

 tions, while the mother returns to it and dies — it is thus her 

 cradle and her tomb." 



Drassus, Walck. 



The Drassi differ from Clotho in several characters. Their, che- 

 licer?e are robust, projecting and dentated beneath ; their jaws are 

 obliquely truncated at the extremity, and the ligula forms an infe- 

 riorly truncated oval, or an elongated curvilinear triangle ; the eyes 

 are nearer to the anterior margin of the thorax, and the line formed 

 by the four posterior ones is longer than the anterior, or extends 

 beyond it on the sides. There is but little difference in the propor- 

 tions of the fusi, and we do not observe between thein the two pecti- 

 niform valves peculiar to Clotho. Finally, the fourth pair of legs, 

 and then the first, are manifestly longer than the others. The Tibise 

 and first joint of the tarsi are armed with spines. 



These Spiders live imder stones, in the fissures of walls, and on 

 leaves ; they construct their cells with an extremely fine white silk. 

 The cocoons of some are orbicular and flattened, and consist of two 

 valves laid one on the other. M. Walckenaer distributes the Drassi 

 into three families, according to the direction and approximation of 

 the lines formed by the eyes, and the greater or less dilatation of the 

 middle of the jaws. 



The species which he calls viridissimus, Hist, des Aran, fascic. 

 IV, 9, and which alone composes his third division, weaves a 

 fine, white, transparent web on the surface of a leaf; under this 

 web it seeks for shelter. I have sometimes observed a similar 

 web on the leaf of the Pear-tree, but the margin was angular 



