358 Alexander Peteunkevitch, 



Evagrus mexicaniis in the same web witli a mature female and a 

 wliole family of j'oung spiderlings. 



The life and habits of the Aviculariids are but little known, 

 partly because the majoritj' of them are natives of tropical countries 

 and more apt to fall into the hands of a coUector than of an in- 

 vestigator and partly because they are preeminently night creatures 

 and only rarely to be seen by daylight. In the species which came 

 under my own Observation, the mother guards the cocoon for a long 

 time. Whether or not the young moult before leaving the mother, I 

 do not know. At first they appear to lead a gregarious life and 

 several individuals make a web in common. Later they separate 

 and are to be found under the bark of fallen trees where some of 

 them construct little webs of their own, somewhat similar to the 

 webs in which certain true spiders hibernate, while other individuals 

 of the same age and species seem to be content with the protection 

 afforded them by the bark. This instinct for spinning a web is 

 gradually lost and in the next stage we find the older but still 

 immature individuals in the holes in the ground. These holes vary 

 considerably according to the species to which the "tarantula" be- 

 longs. Some choose open places such as roads or fields and meadows; 

 others prefer the jungle, while still others utilize natural depressions 

 or holes among the rocks. But in each species all the holes are 

 always alike. Indeed, one wlio is acquainted with all the species 

 of a given locality, is able to identify the species from the looks of 

 the hole and the little web which protects its entrance, for the 

 majority of species spin a tliin. opalescent sheet of web clear across 

 the entrance upon retiring for their daytime rest. The beautiful 

 Eurypelma vagans, a species very common on the Isthmus of Tehuan- 

 tepec, has the entrance to its hole on a level with the surrounding 

 ground and the opalescent sheet of web across the entrance is a 

 sure sign that the spider is "at home". The grey-brown Eurypelma 

 rustica makes a fiinnelshaped superstructure of earth and web and 

 the Hapalopus pentaloris with its pink cephalothorax and red bars 

 on the abdomen is also easily to be recognized by the structure of 

 the entrance to its hole. The diameter and depth of the hole which 

 is usually perpendicular, naturally vary in size and length according 

 to the age of the individual and the composition of the ground. 

 Once only I found a hole of an Eurypelma, having a little excavation 

 in the side of the tube, halfway between the entrance and the 

 bottom, where the spider would take refiige whenever water was 



