1888.] 



NATURAL SCIENCES OF PHILADELPHIA. 



219 



of Mygale with the addition of a silken lining^ which also is carried 

 above the surface and attached to trees (a) or to the adjacent herb- 

 age either in a straight tube (6) or a curved one (c). 





Fig. 8. Nesting Industry of the Territelarise. 

 1. Mygale. 2. Atypus a, A, Abbotii, b, c, A. piceus. 3. Cyrtauchenius. Cteniza 

 and Nemesia. 



Fig. 9. Nesting Industry of the Citigradae. 

 I. Lycosa. 2. L. arenicola. 3, 4. L. tigrina. 



Turning to the corresponding number in the Citigrade series 

 (Fig. 9, 2) we see the burrow slightly silk lined at the mouth, and 

 carried upward above the surface where it is supported by a rude 

 turret. The silken tube is, however, open and is rudimentary as 

 compared with that of Atypus, 



The third members of the two series show a yet closer likeness in 

 in the nest forms viz., that of Cyrtauchenius (Fig. 8, 3) and that of 

 Lycosa tigrina (Fig. 9, 3). The last named spider by that form of 

 surface nest described above (Fig. 9, 4), shows us a rude suggestion 

 of the trap-door spider's nest which, whether spun within a ground 

 burrow (Fig. 8, 4, a), or within the ridges of bark upon a tree (4, b) 

 as with certain Mexican species, has attracted the admiration not 

 only of naturalists but of all observers. It is curious to note, by the 

 way, the tendency of these accomplished nest builders to domicile 

 upon a tree like their American tribal associates, the Purseweb 

 lers. 



1 Some of the large creatures known generally as the Mygalidae or tarantulas 

 I have no doubt silk line their burrows. We might therefore add to this series 

 another and intermediate form of nest between Mygale (1) and Atypus (2) as here 

 givea. 



