Dec, 191 1.] Grossbeck: Emphor bombiformis. 239 



immediately enter one of the holes, sometimes after describing a few 

 small circles over the entrance, remain there for a short time, and 

 leave again. Others would rest lazily at the entrance of their bur- 

 rows, with head and fore part of thorax out, and retire only to 

 reappear in a few moments or fly away. A few others, after a great 

 deal of buzzing, would walk over the pellets rejected in the construc- 

 tion of the holes as if in search of something, but would finally fly 

 away without having accomplished anything. Still others walked 

 about aimlessly or were extremely busy peering into or examining 

 the burrows of their neighbors, entering first one, then another, but 

 remaining in them only for a few moments at most. Occasionally, 

 after entering a burrow, one would back out hurriedly as if pursued, 

 though I saw no pursuer ; at other times one would be met at the 

 entrance by what was presumably the rightful occupant and owner 

 of the nest, who really appeared to look savage, and in such cases the 

 intruder made haste to move on. 



One individual actually entered sixteen holes before finally fly- 

 ing off. The burrow of this bee, it appeared, had been damaged, as 

 several times the bee returned to a broken nest, removed part of the 

 debris and then went off investigating again. 



In beginning a burrow the bee with its fore legs digs furiously 

 in the thin layer of sod material, brushing the fragments away with 

 its hind legs and meanwhile turning around constantly and standing 

 almost on its head as it were. When the hole has attained a depth 

 of half an inch, soil is reached, and then a different method of work- 

 ing is begun. The soil is now moistened with saliva, small pieces 

 are then bitten off with the mandibles and passed upward to the 

 hind legs where with the assistance of the abdomen it is placed at 

 the entrance of the hole. As pellet after pellet is placed in position 

 the bee turns round and round making one circuit in about one minute 

 and a half, and, with the abdomen partly bent under on the venter and 

 moving from side to side, smooths down the interior of the growing 

 turret. During this process the bee now and then emerges from the 

 burrow and standing clumsily over the half completed turret cleans 

 its antennae with its fore legs, and the hind legs with each other. 

 When the turret has reached a height equal to one-half inch, building 

 ceases, but the work of excavation goes on and the pellets, now larger, 

 are brought to the top of the turret, with the hind legs as usual, and 



